Screening of germplasm for specific traits is a continuous pre-breeding process in deriving the drought-tolerant donors required for crop improvement. The study evaluated 17 medium-late duration finger millet genotypes under drought stress (DS) for 28 days during the reproductive stage to identify the traits and genotypes for drought tolerance using different statistical analysis. The photosynthetic rate (by 26.3%), stomatal conductance (by 26.4%), transpiration rate (by 24.8%) and grain yield (by 13.2%) were decreased and found sensitive to DS, but the leaf temperature was increased (4.7%). From the path analysis and multiple linear regression analysis, the mean ear weight and productive tillers were found to contribute to the grain yield significantly under well-watered conditions. While under DS conditions, the mean ear weight, productive tillers and threshing percentage equally contributed to grain yield. Based on the ranking of traits significantly contributing to grain yield, the genotype GE-4683 with a higher mean ear weight (10.65 g) was found superior to the popular variety, GPU-28. The Multiple linear regression equation predicts the possibility to increase the yield of GPU-28 under DS from the existing 360.0 to 459.5 g per square metre (by 29.1%) by the incorporation of three productive tillers instead of the existing two tillers per plant in the MLR equation. An additional 1.0 g of mean ear weight will be able to predict an increased grain yield from 360.0 to 392.0 gm−2, equivalent to 3.60 to 3.92 t/ha (by 9.4%).

Maize is among major field crops which provides food, fodder and various byproducts to the industry. Development of better performing varieties is very important to enhance and strengthen the maize production system. In this study ethyl methanesulfonate (EMS) is used to induce genetic variation in maize. Mutant population was derived from two genotypes 100,003 and 100,004. EMS was applied under three different concentrations of 25, 50 and 75 mM. 25 mM was found as an ideal concentration resulting in maximum survival rate. Total 10 SSRs were used in this study, which amplified 28 alleles with average of 2.7 alleles. Analysis of molecular variance showed significant differences present among individuals. Average heterozygosity for mutants derived from 100,003 and 100,004 was 0.58 and 0.53, respectively. UPGMA analysis characterized the mutants into two main and many sub clusters. According to the principal component analysis, PC 1 and 2 contributed to 64.2% variability with eigenvalue greater than 1. Statistics showed maximum coefficients of variance in traits of leaf area, cobb height and plant height. Promising mutants were also identified and recommended for future breeding programme. In conclusion, EMS mutagenesis is an effective technique to develop novel mutants that can be exploited in future breeding programmes.

Crop germplasm conserved in genebanks, are a fundamental resource of genetic diversity for crop improvement activities, underpinning future food security and sustainable agricultural practices. However, taxonomic errors in genebank germplasm (due to misclassification, contamination and poor data collation) restrict the effective use of this material for correct purpose. Earlier studies investigating species genetic diversity using genebank germplasm, have shown varying levels of taxonomic error within the Brassica species. In response to this reported taxonomic error of global collections, together with the availability of a multiplex PCR (MPCR) marker, targeting the specific chromosomes (A, B and C) of the six Brassica species in U's triangle, this study was undertaken to confirm the taxonomic identity of accessions within the Australian Grains Genebank's (AGG) long-term Brassica collection. A total of 5161 accessions were analysed with MPCR for taxonomic identification, of which, 4842 (93.8%) were confirmed to be consistent (correct) with their labelled taxonomy, while the remaining 319 (6.2%) were identified as taxonomically inconsistent (in-error). Through the evaluation of earlier regeneration and original seed of the error accessions with MPCR, we determined that 80.9% of the taxonomic errors were traced back to the original seed, while 19.1% of errors were the result of genebank seed regeneration handling practices. Results from this study directly enhance information of the AGG Brassica collection and shape directions for distribution, acquisition and regeneration practices within the AGG and potentially other global genebanks, which will facilitate in a more effective use of these valuable genetic resources by researchers and breeders.

Theobroma cacao L. (cacao) is an important tropical crop used to produce chocolate. Evolutionary relationships between cultivated and wild cacao genotypes and their genetic diversity are poorly understood. Exploring phylogenetic diversity and spatial patterns of both cultivated and crop wild relatives can improve the knowledge of the evolutionary history of a crop, giving insights into its cultivation, breeding programmes and conservation. This study identifies biodiversity priority areas in Colombia by calculating phylogenetic diversity indices using a set of 87 single nucleotide polymorphism markers. These were sourced from 279 genotypes conserved in the Corporación Colombiana de Investigación Agropecuaria (Agrosavia) germplasm collection. The Caribbean and North Andes areas exhibited the highest phylogenetic diversity and significantly high relative phylogenetic diversity. We propose that those regions where wild cacao occurs should be prioritized as conservation areas. Besides, cacao lineages that have recently diverged and are present in Arauca, Huila and Nariño areas, with significantly low relative phylogenetic diversity, should be prioritized for breeding programmes. The Amazonia genotypes were closer to the root of the phylogenetic tree, suggesting an older origin than those found in the Andes region. Our study highlights the importance of using T. cacao germplasm from the Amazonia region as a priority to recover relict diversity in breeding programmes and broaden the gene pool of modern cultivated cacao.

In order to enhance genetic potential of chickpea materials from the National University of Córdoba Breeding Programme and Germplasm collection (Argentina), a study for a comprehensive understanding of the amount and pattern of genetic variation within and between genotypes was carried out by applying a multivariate analysis form single simple repeats (SSR) and morphological data. Molecular data were also used to determine the discriminating power for genotype identification, and to find the optimal primer combination to ensure unambiguous identification. With the analysis of 15 SSR markers on 53 genotypes, a total of 58 alleles were detected with individual values ranging from one to nine alleles per locus. High values of discriminating power (Dj ⩾ 0.7, PIC ⩾ 0.7), and low values of confusion probability (Cj ⩽ 0.23) were obtained for at least four evaluated markers. The combination of TA113 + TA114 + H1B09 + TA106 primers was effective for discriminating the 53 chickpea genotypes with a cumulative confusion probability value (Ck) of 9.60 × 10−4. Except for some exceptions, individual chickpea genotypes within a cluster in the consensus tree were definitely more closely related with each other by the origin or pedigree. The results confirmed that both multivariate data analysis methods, ordination and clustering, were complementary. In most genotypes, discriminant principal component analysis classification was consistent with the original clusters defined by molecular data. Differences in results from molecular and morphological data indicate that they provide complementary and relevant information for establishing genetic relationships among chickpea materials and a better description and interpretation of the available variability in the germplasm collection.

Chenopodium quinoa W. is a species of South America with an exceptional nutritional content and wide agroclimatological adaptation. It has great genetic and phenotypic variability, however in Colombia there are few genetic improvement programmes that take advantage of its great genetic and productive potential. In Cundinamarca there are some adapted genotypes which have been selected by farmers. We evaluated 36 genotypes of Blanca de Jericó, Blanca Subachoque, Aurora, Púrpura and Tunkahuan from Cundinamarca, using eight ISSR markers. The analysis by the coefficient of Nei-Li at the level of similarity of 0.40 divided the population into three groups according their background genetic and the colour of oxalates. The percentage of polymorphic loci was higher than 90%. The average value of heterozygosity was 0.32, which is low given the selection processes that the evaluated germplasm has undergone. We found moderate genetic differentiation (Fst = 0.23). The analysis of molecular variance (AMOVA) showed higher variation (77%) groups than among groups (23%). The results revealed intra-population diversity, which suggests that farmers within their farms should undergo a more rigorous seed selection process. Our results demonstrate that ISSR markers are useful and powerful to assess the genetic relationships, polymorphism and genetic diversity of quinoa cultivars. The genetic characterization results reported in the present study will be promising for guiding the breeding of quinoa seed quality in Colombia.

Cashew (Anacardium occidentale L.) is cultivated in more than 30 countries because of its economic and nutritional importance. Despite having a significant agronomic role, little is known about the genetic and phenotypic diversity of cashew populations in Brazil. Thus, we aimed to characterize and estimate the diversity among cashew genotypes based on agro-morphological and physicochemical traits, with an objective of selection of varieties for breeding programmes. Forty-three cashew trees were evaluated based on 13 morphological traits and three physicochemical traits. A wide range of variations was recorded for the phenotypic characteristics, including total weight, fruit weight, pseudofruit length, kernel weight and total acidity, suggesting the existence of considerable variations for potential use in breeding programmes. Principal component analysis explained 79.74% of the total variation in the first two principal axes. The dendrogram based on the UPGMA method classified the 43 genotypes into six groups. Groups IV and VI were the most dissimilar, with emphasis on the genotypes 28 and 43, which were observed to be most divergent based on the Euclidean distance matrix (3.054). This makes it possible to select genotypes for hybridization with F1 generation gains. Based on cluster analysis and comparison of means among the six groups, promising genotypes were identified with superior traits, such as fruit weight, pseudofruit length, kernel weight and total acidity. This suggests the importance of phenotypic characterization for cashew breeding programmes. In addition, the observed vast diversity is an important genetic basis for improving cashew yield in northeastern Brazil.

Chickpea (Cicer arietinum L.) is one of the most important grain legumes after common bean. In the present study, a total of 35 chickpea genotypes including desi and Kabuli types of cultivated chickpea (C. arietinum) were evaluated for seed physical characteristics that are very important for seed storage, processing and determining seed quality traits. Therefore, it has become imperative to study the seed physical characteristics of chickpea during the present study. The analysis of data revealed that substantial variation is present among the genotypes under study with respect to seed physical characteristics such as seed size, seed volume, seed density, hydration capacity, hydration index, swelling capacity and swelling index. These traits are considered important to determine the seed rate at the time of sowing of the crop, cooking quality, storage and processing and thereby have a direct bearing on the economics of chickpea consumption. Our results indicated that the desi, Kabuli and pea-shaped genotypes differ significantly in seed physical characteristics with overall superior trait performance of the Kabuli type compared to other seed types, making them superior with respect to consumer/market demands.