Research Article
De novo assembly, annotation and molecular marker identification from the leaf transcriptome of Ocimum gratissimum L.
- Tanuja, Nibir Ranjan Parasar, Ravichandiran Kumar, Purushothaman Natarajan, Madasamy Parani
-
- Published online by Cambridge University Press:
- 02 December 2021, pp. 469-476
-
- Article
- Export citation
-
Ocimum gratissimum L. is a well-known medicinal plant with several therapeutic properties, but molecular studies on this species are lacking. Therefore, we have sequenced the whole transcriptome from the leaves of O. gratissimum and assembled 121,651 transcripts. The transcriptome of O. gratissimum was closely related to Sesamum indicum and Erythranthe guttata in congruence with the molecular phylogenetic relationships among these species. Further, 62,194 transcripts were annotated and classified according to the GO terms concerning the biological process, cellular component and metabolic function. In the KEGG pathway analysis, 34,876 transcripts were mapped to 149 pathways and 1410 of them were involved in the biosynthesis of secondary metabolites. In the phenylpropanoid pathway, 101 transcripts were associated with the biosynthesis of eugenol, the principal constituent of the essential oil of O. gratissimum. In the caffeine metabolism pathway, none of the transcripts was related to caffeine biosynthesis, supportive of the caffeine-free nature of Ocimum. Transcripts coding for the metallothionein were abundant in the leaves, supporting the observation that O. gratissimum is an accumulator of heavy metals. We also identified the 930 transcripts coding for 59 transcription factors families with myeloblastosis transcription factors being the most predominant. About 6500 simple sequence repeats were identified, which will be useful in DNA marker-based applications. This is the first report of the leaf transcriptome of O. gratissimum, which will serve as an essential resource for further molecular studies in this important medicinal species.
Physiological, biochemical and molecular responses of durum wheat under salt stress
- Mohammad Mehdi Momeni, Mansoor Kalantar, Mahdi Dehghani-Zahedani
-
- Published online by Cambridge University Press:
- 27 April 2021, pp. 93-103
-
- Article
- Export citation
-
The yield of durum wheat extremely reduces in response to salinity stress because of several variations in biochemical, physiological and molecular traits in this unfavorable condition. According to the agro-physiological traits under salinity stress, the most resistant and sensitive cultivars were selected from 10 genotypes of durum wheat over a period of 2 years. Afterwards, the molecular, biochemical, and physiological traits in these two genotypes were evaluated. The seedlings (3–4 leaves) were exposed to salinity through irrigating with 0.5 × Hoagland solution containing 200 mM NaCl until physiological maturity. Principal components analysis for the agronomic characteristics and stress resistance index led to identifying Behrang and Arya as the most tolerant and sensitive genotypes, respectively. In these two genotypes in response to salinity stress, osmolyte contents (proline, total soluble carbohydrates and total soluble proteins) and enzymatic antioxidant defence system activities (ascorbate peroxidase, catalase and guaiacol peroxidase) were much higher in the most tolerant genotype than those of the sensitive cultivar. Moreover, the most tolerant genotype showed less amount of oxidative stress parameters (hydrogen peroxide, electrolyte leakage, malondialdehyde and other aldehydes) than the sensitive one. Pyrroline-5-carboxylate reductase (P5CR) and delta-1-pyrroline-5-carboxylate synthase (P5CS) genes expression increased under salinity stress (considering much higher increase in the most tolerant cultivar). Also, proline content was shown to have a significant positive correlation with P5CS and P5CR genes expression levels. Our result not only identified Behrang cultivar as a superior genotype for durum wheat breeding programs, but also represented several efficient mechanisms involved in salt tolerance.
Genetic diversity and GWAS of agronomic traits using an ICARDA lentil (Lens culinaris Medik.) Reference Plus collection
- Karthika Rajendran, Clarice J. Coyne, Ping Zheng, Gopesh Saha, Dorrie Main, Nurul Amin, Yu Ma, Ted Kisha, Kirstin E. Bett, Rebecca J. McGee, Shiv Kumar
-
- Published online by Cambridge University Press:
- 07 July 2021, pp. 279-288
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Genotyping of lentil plant genetic resources holds the promise to increase the identification and utilization of useful genetic diversity for crop improvement. The International Center for Agriculture Research in the Dry Areas (ICARDA) lentil reference set plus collection of 176 accessions was genotyped using genotyping-by-sequencing (GBS) and 22,555 SNPs were identified. The population structure was investigated using Bayesian analysis (STRUCTURE, k = 3) and principal component analysis. The two methods are in concordance. Genome-wide association analysis (GWAS) using the filtered SNP set and ICARDA historical phenotypic data discovered putative markers for several agronomic traits including days to first flower, seeds per pod, seed weight and days to maturity. The genetic and genomic resources developed and utilized in this study are available to the research community interested in exploring the ICARDA reference set plus collection using GWAS.
Comparative assessment of SCoT and ISSR markers for analysis of genetic diversity and population structure in some Aegilops tauschii Coss. accessions
- Atefeh Nouri, Maryam Golabadi, Alireza Etminan, Abdolmajid Rezaei, Ali Ashraf Mehrabi
-
- Published online by Cambridge University Press:
- 13 October 2021, pp. 375-383
-
- Article
- Export citation
-
Aegilops tauschii, the diploid progenitor of the wheat D-genome, is a valuable genetic resource for wheat breeders. In this study, we compared the efficiency of inter-simple sequence repeat (ISSR) (as an arbitrary technique) and start codon targeted (SCoT) (as a gene-targeting technique) markers in determining the genetic diversity and population structure of 90 accessions of Ae. tauschii. SCoT markers indicated the highest values for polymorphism information content, marker index and effective multiplex ratio compared to ISSR markers. The total genetic diversity (Ht) and genetic diversity within populations (Hs) parameters were comparably modest for the two marker systems. The results of the analysis of molecular variance showed that the genetic variation within populations was significantly higher than among them (ISSR: 92 versus 8%; SCoT: 88 versus 12%). Furthermore, SCoT markers discovered a high level of genetic differentiation among populations than ISSRs (0.19 versus 0.05), while the amount of gene flow detected by ISSR was higher than SCoT (2.13 versus 8.62). Cluster analysis and population structure of SCoT and ISSR data divided all investigated accessions into two and four main clusters, respectively. Our results revealed that SCoT and ISSR fingerprinting could be used to further molecular analysis in Ae. tauschii and other wild species. The high-genetic variability found in this study also indicates the valuable genetic potential present in the investigated Ae. tauschii germplasm, which could be utilized for future genetic analysis and linkage mapping in breeding programmes.
Morphological and ecogeographical diversity analysis of maize germplasm in the high altitude Andes region of Ecuador
- César Tapia, Elena Torres, Nelly Paredes, Mauricio Parra-Quijano
-
- Published online by Cambridge University Press:
- 07 June 2021, pp. 183-194
-
- Article
- Export citation
-
The Andean region of Ecuador is the place of origin of many maize landraces grouped into 24 races. Definition of priorities for maize diversity conservation in this region can be supported by the spatial identification of areas with a high eco-geographical and phenotypic diversity. Six hundred thirty-six maize samples were morphologically characterized using 14 descriptors and assigned to a distinctive race. Additionally, sampled farms were characterized by 12 environmental variables. From these data, maps of morphological and eco-geographical diversity were obtained by using techniques to determine eco-geographical and phenotypic distances and applying them to each geographical neighbourhood. The races Patillo Ecuatoriano, Racimo de Uva and Uchima exhibited high intra-racial morphological variation, particularly in the shape of the ear, kernel row layout, cob diameter and total kernel number. The highest number of different races was observed in Imbabura, Azuay and Chimborazo provinces. The highest levels of morphological diversity were found in three cells (10 × 10 km), located in Pichincha, Chimborazo and Loja provinces. Two ecological niches, located in Loja province, showed high levels of eco-geographical diversity. A comparison between diversity maps revealed shared hotspots of morphological and eco-geographical diversity in the central and southwest areas of Imbabura province. The Andean highlands of Ecuador are an optimal refuge for the conservation of maize diversity, and the criteria of eco-geographical and morphological diversity and race richness should be considered when defining priority in situ conservation areas.
Characterization of flowering time response among recombinant inbred lines of WAB638-1/PRIMAVERA rice under reproductive stage drought stress
- Kehinde A. Adeboye, Olusegun A. Oduwaye, Isaac O. Daniel, Mamadou Fofana, Mande Semon
-
- Published online by Cambridge University Press:
- 17 February 2021, pp. 1-8
-
- Article
- Export citation
-
Ninety-eight high-yielding recombinant inbred lines (RILs) of WAB638-1/PRIMAVERA rice were evaluated with the parents under reproductive stage drought stress. The study aimed at characterizing flowering time response under drought stress and consequently classifying the genetic resources for efficient use in breeding programmes. Two field trials were conducted during the 2016 and 2017 dry seasons using the randomized complete block design with two replications. In 2016, 12 RILs were evaluated with the parents for the rooting attributes under drought stress and well-watered treatments. Analysis of variance revealed a significant (P < 0.05) variation among the genotypes for the traits evaluated. Drought stress reduced most of the characters in this study, including grain yield. However, the inbred lines exhibited considerable tolerance to drought stress as indicated by yield-related stress indexes, including stress susceptibility and drought tolerance indexes. Delayed flowering (FD) was recorded in 75 genotypes (including WAB638-1), while 25 genotypes (including PRIMAVERA) had no delay under drought stress compared to the control. The genotypes were grouped into flowering delay (D) genotypes (FD > 1 d) and no delay (N) genotypes (FD < 1 d), which significantly differ (P ⩽ 0.05) for numbers of days to 50% flowering. The flowering delay genotypes may be suitable for intermittent drought, while genotypes with little or no delay may be selected for terminal drought conditions. There was a significant correlation (r > 0.5) between the root length and number of days to 50% flowering. The study indicated that root parameters, such as the root length, may contribute to the drought adaptation mechanisms of the RILs.
The utility of ISSRs for the identification of interspecific hybrids between pearl millet (Pennisetum glaucum [L.] R.Br.) × napier grass (Pennisetum purpureum Schumach)
- S. S. Jade, P. S. Takawale, R. A. Bahulikar
-
- Published online by Cambridge University Press:
- 23 March 2021, pp. 104-111
-
- Article
- Export citation
-
Interspecific hybrids between pearl millet (Pennisetum glaucum) and napier grass (Pennisetum purpureum) give rise to perennial fodder crops characterized by high biomass, broad clumps and good palatability. These hybrids are triploid and developed by hand pollination of napier grass pollen on pearl millet panicles. The progeny shows a high percentage of pearl millet genotype due to self-pollination in the female parent. Identification of hybrids at a young stage based on morphological characters is difficult. DNA-based molecular markers have high discriminating power and were used to assess genetic differences between hybrids and their parents. Genetic diversity was studied in 18 pearl millet × napier grass hybrids along with their parents and two released national checks using inter simple sequence repeat (ISSR) markers. Eight ISSR primers gave rise to 125 bands, of which 120 bands were polymorphic. Polymorphic information content and ISSR primer index ranged from 0.40 to 0.49 and 8.88 to 11.14, respectively. The hybrids showed the presence of unique bands, besides those shared with male and female parents. Female (pearl millet) parents formed a separate group in the dendrogram constructed based on ISSR polymorphism. The male (napier grass) parents formed a separate group along with hybrids, indicating a higher similarity of hybrids with the male parents. Principal component analysis and STRUCTURE analyses showed a similar grouping. The close resemblance of hybrids to the male parents confirmed their interspecific origin. The study revealed that ISSR marker analysis could be a quick and reliable method to identify interspecific hybrids at an early stage of growth.
Assessing the leaf shape dynamic through marker–trait association under drought stress in a rice germplasm panel
- Mayuri D. Mahalle, S. K. Chetia, P. C. Dey, R. N. Sarma, A. R. Baruah, R. C. Kaldate, Rahul K. Verma, M. K. Modi
-
- Published online by Cambridge University Press:
- 07 January 2022, pp. 477-483
-
- Article
- Export citation
-
The flag leaf acts as a functional leaf in rice, Oryza sativa L., primarily supplying photosynthate to the developing grains and influencing yields to a certain extent. Drought stress damages the leaf physiology, severely affecting grain fertility. Autumn rice of northeast India is called locally as ‘ahu’ rice, and is known for its drought tolerance. Exploring diverse germplasm resources at the morphological level using an association mapping approach can aid in identifying the genomic regions influencing leaf shape dynamics. A marker–trait association (MTA) study was carried out using 95 polymorphic SSR markers and a panel of 273 ahu rice germplasm accessions in drought stress and irrigated conditions. The trials suggest that at the vegetative stage, drought stress significantly affects leaf morphology. The leaf physiology of some tolerant accessions was relatively little affected by stress and these can be considered as ideal varieties for drought conditions. The phenotypic coefficient of variance and genotypic coefficient of variance values implied moderate to high variability for the leaf traits studied. Analysis of molecular variance inferred that 11% of variation in the germplasm panel was due to differences between populations, while the remaining 89% may be attributed to a difference within subgroups formed through STRUCTURE analysis. Using the mixed linear model approach revealed 11 MTAs explaining between 4.5 and 20.0% of phenotypic variance at P > 0.001 for all the leaf traits. The study concludes that ahu rice germplasm is extremely diverse and can serve as a valuable resource for mining desirable alleles for drought tolerance.
Assessment of the genetic diversity and population structure of apricot (Prunus armeniaca L.) germplasm of the Northwestern Himalaya using SSR markers
- Aijaz A. Wani, Khalid Hussain, Showkat A. Zargar, Faizan Ahmad, Reetika Mahajan, Sajad Majeed Zargar, Anzar A. Khuroo
-
- Published online by Cambridge University Press:
- 17 September 2021, pp. 384-393
-
- Article
- Export citation
-
Apricot is considered an ecologically and economically important tree species of the stone-fruit crops that is widely grown in temperate regions of the world. Very few studies on apricot genetic diversity assessment have been carried out from the regions of Kashmir and Ladakh. In this backdrop, the present study was carried out to analyse the genetic diversity and population structure of 120 apricot genotypes collected from both the regions using 21 SSR markers. A total of 52 alleles were amplified with average values of marker index (MI) = 0.7084, resolving power (RP) = 2.8690, polymorphism information content (PIC) = 0.3132, Na = 2.317, Ne = 1.720, I = 0.572, Ho = 0.284, He = 0.360 and an average polymorphism of 91.2% per assay indicating high level of genetic diversity. The neighbour-joining (NJ) dendrogram generated three main clusters among selected apricot genotypes independent of their geographical locations. Interestingly, the result of the dendrogram coincides with the results of structure analysis which showed that the 120 apricot genotypes could be assigned to three (K = 3) sub-populations and the grouping of genotypes did not follow their geographical location suggesting that they share the same genetic pool. Moreover, analysis of molecular variance showed that 73% of the variation was attributed to differences within the individuals, 25% among individuals while only 2% of the variation was observed among the populations. The present study represents the most comprehensive analysis of the genetic diversity and population structure of apricot genotypes in Kashmir and Ladakh regions of India.
Haplotype analysis of Saltol QTL region in diverse landraces, wild rice and introgression lines of rice (Oryza sativa L.)
- K. K. Manohara, Shaiesh Morajkar, Yogini Shanbhag, Pratham Phadte, Nagendra Kumar Singh
-
- Published online by Cambridge University Press:
- 25 May 2021, pp. 289-298
-
- Article
- Export citation
-
Salt stress is a major abiotic stress affecting the productivity of rice crop worldwide. This study screened a set of 71 rice genotypes collected from coastal parts of Goa and Karnataka states in India for seedling stage salinity tolerance to identify genotypes alternative to standard salt-tolerant donors Pokkali, FL478, etc. Phenotyping for seedling stage tolerance was carried out under micro plots at an induced salinity of 12 dS/m. For haplotyping, 14 Saltol QTL linked simple sequence repeat (SSR) markers on chromosome 1 were utilized. On the basis of the response to salt stress, 10 genotypes were found tolerant, 16 moderately tolerant, 29 sensitive and 15 as highly sensitive. Among the SSR markers, marker RM10871 was the most polymorphic with a polymorphic information content of 0.90, exhibiting 14 different alleles followed by RM10793 (0.84) and RM3412 (0.80) with 8 and 7 alleles, respectively. These markers also exhibited high values for the effective number of alleles (Ne) and gene diversity (I). The haplotype analysis revealed that the allelic constitution of the Saltol region of 10 tolerant genotypes from our study varied in comparison to the reference tolerant check FL478. Further, the haplotype of three tolerant genotypes, namely, Goa Dhan 2, Panvel 1 and Goa wild rice (GWR) 005 appears to be completely different from the FL478 haplotype indicating tolerance in these genotypes is controlled by genomic region other than Saltol. These three genotypes with probable novel regions for seedling stage salt tolerance can be considered for enhancing salinity tolerance of rice cultivars.
Estimating genetic diversity, mating system and pollen dispersal to inform ex situ conservation of the tree Genipa americana L.
- Marília Freitas de Vasconcelos Melo, Alexandre Magno Sebbenn, Bruno Cesar Rossini, Ana Veruska Cruz da Silva Muniz, Carlos Jose Rodrigues, Celso Luis Marino, Mario Luiz Teixeira de Moraes
-
- Published online by Cambridge University Press:
- 01 March 2021, pp. 9-19
-
- Article
- Export citation
-
Using microsatellite loci, we assessed the mating system and genetic diversity of the dioecious tropical tree Genipa americana in a natural population (NP) and a progeny test (PT). For NP, we also estimated the paternity correlation within and among fruits and mean pollen dispersal distance. As expected for dioecious species, all offspring originated from outcrossing (t = 1). Mating among relatives (1 − ts) and paternity correlation (rp) were variable among progenies (1 − ts = 0.03–0.19; rp = 0.04–0.40), but greater in NP than in PT. Fixation index (F) was generally significant and lower in adults than in offspring, indicating selection against inbred individuals. Paternity correlation was higher within (0.40) than among (0.26) fruits, indicating a lower effective number of pollen donors (Nep) within (2.5) than among (3.8) fruits. Due to the higher rp in NP, the effective size within progenies (Ne) was lower (2.69) than PT (3.27). The pollen dispersal pattern was strongly leptokurtic, suggesting long-distance pollen dispersal (mean of 179 m). The results show that both populations can be used for seed collection in environmental reforestation programmes; however, considering that PT is structured in maternal progenies, NP is more suitable for seed collection due to the lower probability of mating among related trees.
Association mapping of genomic loci linked with Fusarium wilt resistance (Foc2) in chickpea
- Uday Chand Jha, Rintu Jha, Abhishek Bohra, Lakshmaiah Manjunatha, Parasappa Rajappa Saabale, Swarup K. Parida, Sushil Kumar Chaturvedi, Virevol Thakro, Narendra Pratap Singh
-
- Published online by Cambridge University Press:
- 21 April 2021, pp. 195-202
-
- Article
- Export citation
-
Improving plant resistance against Fusarium wilt (FW) is key to sustaining chickpea production worldwide. Given this, the current study tested a set of 75 FW-responsive chickpea breeding lines including checks in a wilt-sick plot for two consecutive years (2016 and 2017). Genetic diversity analysis using 75 simple sequence repeats (SSRs) revealed a total of 267 alleles with an average of 3.56 alleles per marker. The entire set was divided into two major classes based on clustering method and factorial analysis. Similarly, STRUCTURE analysis placed the 75 genotypes into three distinct sub-groups (K = 3). Marker-trait association (MTA) analysis using the generalized linear model approach revealed nine and eight significant MTAs for FW resistance in the years 2016 and 2017, respectively. Three significant MTAs were obtained for FW resistance following the mixed linear model approach for both years. The SSR markers CESSR433, NCPGR21 and ICCM0284 could be potentially employed for targeted and accelerated improvement of FW resistance in chickpea. To the best of our knowledge, this is the first report on association mapping of the genomic loci controlling FW (Foc2) resistance in chickpea.
Vegetative propagation, chemical composition and antioxidant activity of yerba mate genotypes
- Leandro Marcolino Vieira, Renata de Almeida Maggioni, Jéssica de Cássia Tomasi, Erik Nunes Gomes, Ivar Wendling, Cristiane Vieira Helm, Henrique Soares Koehler, Katia Christina Zuffellato-Ribas
-
- Published online by Cambridge University Press:
- 30 March 2021, pp. 112-121
-
- Article
- Export citation
-
Ilex paraguariensis, commonly known as yerba mate, is a tree species native to South America. Its commercial value is due to the manufacturing of teas, with potential also in the pharmacological and cosmetic industries. Vegetative propagation of yerba mate is considered an innovation to the traditional production systems based on sexual propagation. The present study aimed to evaluate the rhizogenic potential and chemical attributes of mini-cuttings from 15 yerba mate genotypes, as well as to verify the correlation between phytochemical and rooting-related variables. Mini-cuttings were collected from a pre-existing mini-clonal hedge and the experimental design was completely randomized, with 15 treatments (genotypes), four replications and 10 mini-cuttings per plot. After 120 days, mini-cuttings were assessed regarding rooting, mortality, callogenesis and leaf retention percentages, percentage of mini-cuttings with both calluses and roots, number of roots and average root length. At the time of collection, subsamples from each plot were used for phytochemical analyses including total phenolic compounds, protein, caffeine and theobromine contents and antioxidant activity. Rooting percentages ranged from 5 to 72.5%, with significant variation among genotypes. Adventitious rooting and phytochemical profile of yerba mate mini-cuttings are genotype-dependent. Leaf retention is a relevant factor in the rooting of yerba mate mini-cuttings and the levels of total phenolic compounds, antioxidants and theobromine present in mini-cuttings are negatively correlated components to Ilex paraguariensis adventitious rooting.
Analysis of phenotypic diversity of apricot (Prunus armeniaca L.) accessions from Jammu and Kashmir, India
- Showkat A. Zargar, Aijaz A. Wani, M. I. S. Saggoo
-
- Published online by Cambridge University Press:
- 27 April 2021, pp. 203-215
-
- Article
- Export citation
-
Apricot (Prunus armeniaca L.) is a world-wide highly appreciated fruit, with its attractive colour, soft texture and typical flavour. In the current investigation, 68 apricot accessions collected from Jammu and Kashmir, India were analysed to determine the measure of variation using 12 qualitative and 16 quantitative traits with an aim to identify superior apricot accessions with excellent fruit quality traits. High phenotypic variability was observed among the studied apricot accessions with significant differences among most of the qualitative and quantitative traits. Fruit-related characteristics including fruit weight, fruit length, fruit ratio, fruit firmness, fruit shape, fruit suture, stone weight, kernel weight and stone shape were the most diverse with a high coefficient of variation (>30%). One way analysis of variance showed significant differences (P < 0.0001) among all the quantitative traits. Significant positive and negative correlations were observed between all the agronomically important fruit quality traits. The principal component analysis (PCA) revealed that 75.34% of the variability was defined by the first eight components. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram, based on all traits measured grouped the accessions into two main clusters with several sub-clusters. Both UPGMA dendrogram and PCA scatter plot formed a cluster of 14 accessions, having the highest values regarding most important fruit quality traits such as fruit weight, fruit length and width, fruit ratio, stone weight and kernel weight can be treated as potentially superior accessions. These accessions can be used directly for cultivation and in future apricot breeding programmes. The present findings are promising for genetic resource management, cultivar improvement and commercial applications of apricot in Jammu and Kashmir, India.
Genome-wide association study of physical and microstructure-related traits in peanut shell
- Kailu Cui, Feiyan Qi, Ziqi Sun, Jingjing Feng, Bingyan Huang, Wenzhao Dong, Xinyou Zhang
-
- Published online by Cambridge University Press:
- 08 October 2021, pp. 394-404
-
- Article
- Export citation
-
Peanut shell plays key roles in protecting the seed from diseases and pest infestation but also in the processing of peanut and is an important byproduct of peanut production. Most studies on peanut shell have focused on the utilization of its chemical applications, but the genetic basis of shell-related traits is largely unknown. A panel of 320 peanut (Arachis hypogaea) accessions including var. hypogaea, var. vulgaris, var. fastigiata and var. hirsuta was used to study the genetic basis of two physical and five microstructure-related traits in peanut shell. Significant phenotypic differences were revealed among the accessions of var. hypogaea, var. hirsuta, var. vulgaris and var. fastigiata for mechanical strength, thickness, three sclerenchymatous layer projections and main cell shape of the sclerenchymatous layer. We identified 10 significant single nucleotide polymorphisms (SNPs) through genome-wide association study (P < 5.0 × 10−6) combining the shell-related traits and high-quality SNPs. In total, 192 genes were located in physical proximity to the significantly associated SNPs, and 11 candidate genes were predicted related to their potential contribution to the development and structure of the peanut shell. All SNPs were detected on the B genome demonstrating the biased contribution of the B genome for the phenotypical make-up of peanut. Exploring the newly identified candidate genes will provide insight into the molecular pathways that regulate peanut shell-related traits and provide valuable information for molecular marker-assisted breeding of an improved peanut shell.
A novel parent selection strategy for the development of drought-tolerant cotton cultivars
- Waqas Shafqat Chattha, Hafiz Basheer Ahmad, Muhammad Awais Farooq, Waqar Shafqat, Muhammad Yaseen, Muhammad Zahid Ihsan, Fahad Alghabari, Saleh Mahdi Alzamanan
-
- Published online by Cambridge University Press:
- 07 June 2021, pp. 299-307
-
- Article
- Export citation
-
Drought is a devastating factor for crop production worldwide. Therefore, an experiment was conducted to study genetics for some agro-physiological traits in cotton under drought stress. The 13 parental cotton genotypes along with their 30 F1 hybrids were planted under normal and drought conditions. The mean performance of the genotypes was assessed through principal component and heat map analyses. The principal component analyses revealed 53.99 and 53.15% in the first two principal components of variability for normal and drought conditions, respectively. Heat map analysis revealed that three cotton genotypes i.e. FH-207 × NS-131, FH-207 × KZ-191 and S-15 × AA-703 attained higher values for all the traits except for canopy temperature under drought conditions. These crosses may proliferate to further filial generations to identify transgressive segregates for drought tolerance. The heritable differences of F̅1 and mid-parent showed dominance and non-additive gene action under drought conditions. Heritable differences between F̅1 and P̅1 showed over dominance and partial dominance under drought conditions. Heritable differences between F̅1 and P̅2 indicated negative over dominance and partial dominance for all traits under drought conditions. Proline contents and the bolls per plant showed high heritability and genetic advance through additive gene action. Therefore, these two traits can be used as a means of selection in future breeding programmes of drought tolerance.
Assessment of diversity in tropical soybean (Glycine max (L.) Merr.) varieties and elite breeding lines using single nucleotide polymorphism markers
- Abush Tesfaye Abebe, Adesike Oladoyin Kolawole, Nnanna Unachukwu, Godfree Chigeza, Hailu Tefera, Melaku Gedil
-
- Published online by Cambridge University Press:
- 17 February 2021, pp. 20-28
-
- Article
- Export citation
-
Soybean (Glycine max (L.) Merr.) is an important legume crop with high commercial value widely cultivated globally. Thus, the genetic characterization of the existing soybean germplasm will provide useful information for enhanced conservation, improvement and future utilization. This study aimed to assess the extent of genetic diversity of soybean elite breeding lines and varieties developed by the soybean breeding programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The genetic diversity of 65 soybean genotypes was studied using single-nucleotide polymorphism (SNP) markers. The result revealed that 2446 alleles were detected, and the indicators for allelic richness and diversity had good differentiating power in assessing the diversity of the genotypes. The three complementary approaches used in the study grouped the germplasm into three major clusters based on genetic relatedness. The analysis of molecular variance revealed that 71% (P < 0.001) variation was due to among individual genotypes, while 11% (P < 0.001) was ascribed to differences among the three clusters, and the fixation index (FST) was 0.11 for the SNP loci, signifying moderate genetic differentiation among the genotypes. The identified private alleles indicate that the soybean germplasm contains diverse variability that is yet to be exploited. The SNP markers revealed high diversity in the studied germplasm and found to be efficient for assessing genetic diversity in the crop. These results provide valuable information that might be utilized for assessing the genetic variability of soybean and other legume crops germplasm by breeding programmes.
Genetic architecture, physio-biochemical characterization and identification of elite cytoplasmic male sterile (pt-CMS) based combiners in developing antioxidant-rich carrot
- Hemant Ghemeray, Raj Kumar, T. K. Behera, V. K. Sharma, Saurabh Singh, Reeta Bhatia, S. S. Dey
-
- Published online by Cambridge University Press:
- 19 January 2022, pp. 484-496
-
- Article
- Export citation
-
Existence of genetic divergence, appropriate characterization of breeding lines for economically important traits and determining parents with favourable alleles is the crux of crop genetic improvement programmes. This study is the first report of unravelling genetics and potential of petaloid-type cytoplasmic male sterile (pt-CMS) lines in carrot. Ten pt-CMS lines were crossed with 10 inbreds in line × tester mating fashion to generate 100 testcross progenies. Nutritional profiling of the 100 testcrosses progenies along with 20 parental types was carried out for two consecutive years for eight important traits to identify superior combiners. The pooled analysis revealed that the carotenoid content in root is under the genetic control of major genes (oligogenic). The pooled analysis revealed less than unity value of σ2A/D and σgca2/σsca2 for majority of the traits depicting preponderance of non-additive gene effects. The pt-CMS lines KT-28A, Kt-62A, KT-80A and KT-95A were identified as good combiners for carotenoids. The cross combination, KT-98A × KS-50 identified as the best heterotic combiner for CUPRAC and FRAP content over the years. Similarly, the combinations, KT-62A × KS-21, KT-80A × New Kuroda and KT-62A × KS-59 were found promising across the years for developing nutritionally rich F1 hybrids. The interaction analysis among the different antioxidant traits and plant pigments unveiled the scope of simultaneous improvement.
Morpho-agronomic traits variability, allelic polymorphism and diversity analysis of African yam bean: towards improving utilization and germplasm conservation
- David Adedayo Animasaun, Vincent Ochos Adikwu, Gabriel Ameh Alex, Tomi Philips Akinsunlola, Olabisi Fatimo Adekola, Ramar Krishnamurthy
-
- Published online by Cambridge University Press:
- 26 April 2021, pp. 216-228
-
- Article
- Export citation
-
This study assessed the genetic diversity of African yam bean (AYB) accessions using morphological and molecular markers. The accessions were grown, and morphological data collected were subjected to analysis of variance and multivariate analyses. Genomic DNA extracted from the accessions were amplified with inter simple sequence repeat (ISSR) markers. The diversity analysis was conducted using MEGA4 software. The accessions varied significantly (P < 0.05) in growth, flowering and seed-related parameters. Flowering commenced early in most accessions. Weight of 100-seed range from 15.01 to 21.15 g with the mean value of 18.30 g. Significant correlations existed between stem height, the number of leaves and leaf dimensions. Also, days to flowering correlated with pod formation; likewise, seed dimension had a positive association with seed weight. The principal biplot revealed that two components accounted for 41.77% of the observed variation. Analysis of the electropherogram showed 95 loci comprising 1351 alleles were detected by the ISSR markers with 65.26% polymorphism and combined polymorphic information content of 0.85. The principal coordinate analysis placed accessions together on a plane based on their spatial relationship. The dendrogram showed accession pairs (TSs-77, TSs-95) and (TSs-111, TSs-84) are closely related. The phylogram identified three kinships with a total length of 454. Accession TSs-115 is likely the progenitor while TSs-82 and TSs-86 are the most recent. The study concluded that a combination of morphological and ISSR markers is effective for the diversity study of AYB and the existing, genetic diversity in the accessions could be harnessed for its improvement, conservation and utilization.
Comparison of multiplex PCR kits for SCoT and SRAP genotyping in plants
- Ponsit Sathapondecha, Lathapol Boonsermsukchareon, Sukhuman Whankeaw
-
- Published online by Cambridge University Press:
- 24 February 2021, pp. 29-34
-
- Article
- Export citation
-
Taq polymerase system is one of the key success factors for genotyping by using semi-random marker types. Start codon targeted (SCoT) and sequence-related amplified polymorphism (SRAP) are semi-random markers that amplify more than one target at a time, like in multiplex PCR. Here, we compared the performance of five multiplex PCR kits (QIAGEN®, Thermo Scientific™, New England Biolabs, KAPA Biosystem and iNtRON Biotechnology) and Taq DNA polymerase from Vivantis as a representative common Taq polymerase. The PCR using three SCoT and three SRAP markers was performed in six plants, which were different in genome size, including three monocotyledons (rice, oil palm and onion) and three dicotyledons (holy basil, chilli pepper and eggplant). The overall results demonstrated consistent high performance of the Taq polymerase system with the multiplex PCR kit from KAPA Biosystem. Considered by plant, the multiplex PCR kit from KAPA Biosystem showed the best performance in holy basil, eggplant, oil palm and chilli pepper, whereas in rice, the Taq DNA polymerase from Vivantis generated better results than the KAPA Biosystem. In onion, multiplex PCR kit from Thermo Scientific™ showed the best performance among those tested, even if it did not perform well in the other plans. Different Taq polymerase systems might generate different band patterns, therefore using the same Taq polymerase system within one experimental dataset is recommended. The multiplex PCR kit from KAPA Biosystem is the best starting choice.