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.

Oilseed rape is a very undeveloped crop with regard to efficiency of production and the agronomic practice used to maximize its potential. The genetic potential to modify oilseed rape is limited by the narrow genetic base found within the breeding gene pool, resulting in limited novel variation available for exploitation. Novel variation is, however, present in wild diploid ancestors of oilseed rape and has been made available by developing synthetic Brassica napus. This is illustrated through the use of this material to develop an understanding of pod shattering which is one of the most agronomically important characteristics of the crop. Through a variety of approaches it is shown how progress has been made to understand this trait and how this understanding is being used to improve the crop such that efficiency of production will be enhanced.

Leaf colour characteristics of 730 sweetpotato, Ipomoea batatas (L.) Lam. (Convolvulaceae), plant introduction (PI) accessions from the USDA sweetpotato germplasm collection were evaluated during 2012–2014. Colorimetry data for the abaxial and adaxial leaf surfaces were recorded using a tristimulus colorimeter and the CIE 1976 L*a*b* and CIE L*C*h* colour spaces. Most accessions (725 of 730 PIs) had dark-to-medium green leaves, but two PIs had totally purple leaves, and three PIs had yellow or yellow-green (chartreuse) leaves. For mature, field-grown green leaves, values for the red-green coordinate (a*) averaged −12.4 for the adaxial and −10.4 for the abaxial leaf surface. Values for the blue-yellow coordinate (b*) averaged 17.2 for the adaxial and 17.3 for the abaxial leaf surface. Hue angle (h*) for green leaves averaged 120.9° for the adaxial and 126.2° for the abaxial leaf surface. Colour saturation (Chroma, C*) averaged 21.3 for the adaxial and 20.2 for the abaxial leaf surface. Lightness (L*) averaged 35.4 for the adaxial and 47.2 for the abaxial leaf surface of green leaves. Late in the season, over one-half (53.9%) of the 730 PIs showed some level of purple pigmentation in the leaf lamina. Late-season purple leaves were collected and colour coordinates were recorded for 118 PIs grown in the field. For purple leaves, values for a*, b*, C*, L* and h* averaged 2.3, 6.2, 7.9, 28.2 and 64.4° for the adaxial surface and −1.0, 12.7, 13.9, 43.1 and 87.0° for the abaxial leaf surface, respectively.

Double ‘free-hybrids’ (DH) in alfalfa were obtained by crossing in a diallelic scheme, six multiplied simple hybrids (SH) derived from four partly inbred (S2) lines. Analysis of the specific combining ability demonstrated that the main source of variation was for dry matter yield (DMY) in DHs and supported heterosis values of DHs versus the best parent of an average +45% (ranging from +5 to +76%). Investigation at the molecular level was carried out by analysis of simple sequence repeat markers on the six parental SHs and 15 DH progenies and by comparison of gene expression profiles using microarrays of a single DH line to its parental lines. The variation of heterozygosity estimates of the DHs explained a small part (about 20%) of their variation in DMY, while the number of alleles was significantly related to DM performance (r = 0.61; P < 0.05). The microarray analysis identified genes with both significant additive and non-additive levels of expression in the hybrid compared with the parents. The majority of the variation in gene expression was additive (87%), but among the genes with a non-additive pattern of expression, the greater proportion of probe sets (86%) fell outside the parental range. Gene ontology analysis of these genes revealed the presence of a number of terms related to metabolism and genetic information processing.

Germplasm lines with resistance to the sugarbeet root maggot (SBRM) have been developed and released to the public, providing a means to generate hybrids with resistance against the most devastating insect pest of sugarbeet in North America. Effective use of this germplasm, however, requires knowledge of relative strengths of SBRM resistance between lines and knowledge of the diversity and genetic relationships between germplasm. Therefore, field studies comparing SBRM resistance of four released SBRM-resistant germplasm lines (F1015, F1016, F1024 and F1043), a SBRM-resistant parent (PI 179180) and an unreleased SBRM-resistant population (F1055) were performed, and genetic analysis of the diversity and relationships between SBRM-resistant germplasm and their available parents was conducted using simple sequence repeat (SSR) markers. Under natural SBRM infestations, resistant germplasm exhibited significantly less SBRM damage than a susceptible control, with similar, high levels of resistance in F1016, F1024, F1043, F1055 and PI 179180 and lower resistance in F1015. SSR analysis revealed genetic similarities between F1016, F1024 and F1055, while F1015 and F1043 were genetically distinct from these lines. Among resistant genotypes, F1015 and F1043 exhibited greatest and least within-line genetic diversity, indicating greater and lesser inbreeding for F1043 and F1015, respectively. Similarities in damage ratings and genetics for F1016, F1024 and F1055 indicate that these lines are likely to be equally effective at introducing SBRM resistance into elite populations and in combining ability. In contrast, F1043, with its unique parentage and genetic dissimilarity from other resistant lines, provides a genetically distinct, but similarly effective, source of SBRM resistance.

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.

Emmer wheat (Triticum turgidum ssp. dicoccum) is one of the most promising gene sources for drought tolerance improvement of durum wheat (Triticum turgidum ssp. durum). Achieving desired results requires a conscious choice of crossing parents based on general and specific combining ability (GCA and SCA) and also understanding the genes action involved in controlling the desired traits. In this study a 12 × 12 full diallel cross was performed using four emmer and eight durum wheats. The 132 hybrid progenies along with their parental lines were field evaluated under water-stressed and non-stressed conditions. Based on the Griffing diallel analysis both GCA and SCA effects were highly significant for all measured traits under both water treatments indicating possibility of improvement for drought tolerance. In this respect, the amount of additive effect was higher than the non-additive suggesting the chance for genetic advancement through selection. Based on Hayman's graphical analyses under the two water conditions it was revealed that several grain yield component traits were under the control of partial dominance. In contrary, grain yield and most morphological traits showed either dominance or over-dominance gene action. Grain yield had a significant positive correlation with the number of kernels per spike, kernel diameter, grain weight per spike and harvest index. These traits also had greater share of additive effects, relatively high narrow-sense heritability and high Baker ratio suggesting effective indirect selection for grain yield. Most durum × emmer hybrids had grain yield and drought tolerance indices better than the parents indicating that Iranian emmer wheats have a great genetic potential for drought tolerance improvement of durum wheat.

We developed a multiplex PCR DNA marker for quick and easy identification of the AAGG-genome timopheevii lineage, including Triticum timopheevii, Triticum araraticum and hexaploid Triticum zhukovskyi (AAAmAmGG), and the AABB-genome emmer wheat lineage, including Triticum durum, Triticum dicoccum and Triticum dicoccoides. Distinguishing between tetraploid AAGG- and AABB-genome wheat species based on morphology is known to be difficult. This multiplex PCR system is based on the simultaneous PCR amplification of two chloroplast regions, matK and rbcL. The matK region molecularly distinguishes the two lineages, whereas the rbcL region is a positive control amplicon. We also examined whether the simple sequence repeat is a fixed mutation within species, using genetic resources in the collection of KOMUGI, Kyoto University, which comprises accessioned species collected across diverse geographical areas. The multiplex PCR marker distinguished AAGG from AABB species with complete accuracy.

Sweet sorghum is highly coveted to contribute and take up food and energy challenges. A collection of 84 West Africa landraces mostly from Senegal and four control cultivars were screened to identify relevant accessions and trait combination for multi-purpose (sugar/grain/biomass). The implication of photoperiod sensitivity was particularly addressed. A total of 20 traits related to phenology, morphology, grain and sugar production were assessed in two sowing dates (July and August) at CNRA Bambey in Senegal. Late sowing resulted in shortened vegetative phase and a significant decrease in traits related to plant size, stem sugar, biomass and grain productions. Broad-sense heritability was moderate to high for most of the phenology, morphology, grain and sugar-related traits, suggesting their interest for breeding. All the traits related to plant size were positively correlated with plant sugar production except plant height. A cluster analysis identified three groups contrasting in their ability to combine sugar, grain or fodder production based on 18 traits measured for the early sowing. Clusters I and III were suitable for one purpose: grain and sugar, respectively. Cluster II was the most suitable for multi-purpose, showing the best trade-off among grain, sugar and vegetative biomass production. The best accessions for stem sugar yield belonged to durra, caudatum and their intermediate types. The relationship between internode size and sweetness should be further studied, in particular exploring their relationship with internode tissue anatomy. Further studies are also needed to evaluate the role that stay-green can play in sugar yield maintenance under post-flowering drought.

Sri Lanka has a valuable repository of germplasm collection due to the availability of a large number of different traditional and improved rice varieties. Molecular techniques can increase the effectiveness of traditional technologies in assessing genetic diversity. Amplified fragment length polymorphism (AFLP) was used to evaluate the genetic diversity among rice varieties available in the germplasm collection of Plant Genetic Resources Centre, Sri Lanka. AFLP analysis of rice varieties using ten different primer combinations yielded a total of 772 polymorphic bands (98.4%). Genetic similarities were estimated using Jaccard's (J) similarity coefficient. Unweighted pair group method with arithmetic mean (UPGMA)-based dendrogram was constructed. Genetic similarities varied from 0.073 to 0.565. Cluster analysis by genetic similarity divided the accessions into four main groups. The Cophenetic correlation with r = 0.781 indicated high confidence of AFLP data to group the varieties in UPGMA clusters. Principal component analysis further confirmed the patterns obtained by the cluster analysis. The results revealed very high genetic diversity at molecular level among the Sri Lankan rice varieties used in this study.

Inhibition of α-glucosidase activity is considered an effective means for controlling diabetes by regulating glucose uptake, and blueberries have been shown to possess high levels of inhibitory activity. In the present study, we examined the variations in α-glucosidase inhibition, phenolic and anthocyanin levels, and antioxidant capacity in the peel and pulp of 16 mixed-species rabbiteye hybrids (Vaccinium ashei Reade × Vaccinium spp.), one rabbiteye cultivar (V. ashei) and two highbush hybrids (Vaccinium corymbosum). Peel tissue had, on average, about four times higher levels of α-glucosidase inhibitory activity than pulp, and exhibited significantly higher levels of all other measured activities, even though the peel comprised only a small portion of the fruit. Significant variations in the levels of antioxidant activity were observed; however, no consistent differences were observed between the hybrids with various species composition. Significant positive correlations (r≥ 0.84) were found among α-glucosidase inhibitory activity, total anthocyanin (TA) and phenolic levels, and scavenging activity against ROO∙, ∙OH, 1O2 and H2O2 radicals in the extracts from the peel and pulp. There was a high correlation observed between α-glucosidase inhibitory activity levels and ROO∙(ORAC)peel (r= 0.95). A similarly high correlation with TApeel (r= 0.93) suggests that TA would be a suitable assay proxy if a broader genotypic evaluation of blueberry genotypes is desired.

Choclero is a Chilean traditional floury maize, consumed as a vegetable, with large economic and cultural value due to its culinary properties that give unique characteristics to the traditional local cuisine. Market diversification demands new materials with different ear and kernel characteristics, which are at present not fulfilled by breeders due to lack of genetic diversity. At present, the Instituto de Investigaciones Agropecuarias has a Choclero germplasm collection composed of 96 accessions, which can supply this lack of diversity, or increase the gene pool. In the present study, 34 selected Chilean Choclero landraces were characterized for 41 agromorphological traits. Phenotypic evaluation in three environments representative of the core production area revealed significant genetic variability for most of the evaluated traits, leading to the identification of several promising accessions. The greater contribution of genotype in most phenological plant, ear and kernel traits suggest their potential usefulness for breeding purposes. Principal component analysis explained over 75% of the total variation for 29 quantitative agromorphological traits. Cluster analysis separated accessions into four major groups, differentiated mainly by plant phenology and ear trait. These findings indicate a number of useful traits at an intra-racial level and a wide range of phenotypic variation that provides a good source of diversity for use in the development of new Choclero varieties.

A collection of 18 landraces of common bean (Phaseolus vulgaris L.) from northern Portugal was evaluated for both phaseolin pattern and a set of qualitative and quantitative traits. The phaseolin Contender and Tendergreen types were the most commonly occurring, with Boyaca and Huevo de Huanchaco present, but rare. The colour of the flower standard and wing, and seed shape, colour and size were all highly variable. On the basis of morphological traits, the landraces and testers clustered into two main groups. No relationship was found between phaseolin profile and any of the quantitative traits measured. Based on phaseolin patterns, the origin of Portuguese common bean populations was probably the Andean region of South America.

The genus Limnanthes (Limnanthaceae), also known as meadowfoam, has attracted attention for industrial use due to the unique characteristics of its seed oil. Samples from wild populations showed variability in agronomically important traits involved in seed oil yield, warranting the establishment and continued development of a germplasm collection. The level of genetic diversity within the United States Department of Agriculture, Agriculture Research Service, National Plant Germplasm System (USDA-ARS-NPGS) Limnanthes collection was evaluated using 15 simple sequence repeat (SSR) markers across 62 accessions representing 7 species. Parsimony analysis separated the accessions into two main groups consistent with the traditional taxonomic sections Inflexae and Reflexae, but there was little resolution within groups. These two groups were confirmed using neighbour-joining analysis and principal coordinate analysis. SSR marker variation suggests that the Limnanthes germplasm collection is genetically diverse and the accessions within the species likely contain novel alleles, and therefore the collection contributes to the conservation of the wild Limnanthes gene pool.

Andean arracacha (Arracacia xanthorrhiza Bancr.) is a valuable but poorly known vegetatively reproduced root crop whose origin is still unresolved. Wild tuberous forms are present in the presumed areas of domestication and have a perennial or monocarpic life history. To elucidate the origin of the cultivated form, we surveyed a molecular analysis with amplified fragment length polymorphisms (AFLPs) in a representative sample of this crop and its wild relatives from Ecuador and Peru, the presumed areas of domestication. Wild species with tuberous and non-tuberous roots were included, as well as the perennial and monocarpic forms of the presumed wild ancestor. While the two wild varieties of A. xanthorrhiza were closest to the cultivars, they were distinguished by AFLPs. Unexpectedly, two clearly distinct groups were formed among the cultivars, one of which was significantly closer to the monocarpic wild form. However, the chloroplast DNA survey revealed greater similarity between all of the cultivars and the wild perennial A. xanthorrhiza. These results combined with the morphological and life history features, confirms the hypothesis that arracacha domestication started from the wild perennial form. We suggest this scenario of domestication followed by an unsuspected introgression in the cultivation, resulting in two cryptic genetic groups, well distinguished at the molecular level. This is an important revelation with implications in genetic resource conservation and breeding standpoints in this promissory crop.

Genetic diversity of 30 common vetch (Vicia sativa L.) lines and cultivars obtained from various resources or collected from natural flora of Turkey was evaluated by using 55 sequence-related amplified polymorphism (SRAP) and five inter-simple sequence repeat (ISSR) primer sets, and their nuclear DNA contents were determined by flow cytometer. A total of 188 polymorphic loci were detected, with an average of 3.62 loci per primer. The percentage of polymorphic loci was 82.1%. The polymorphism information content values ranged from 0.12 to 0.96, with an average of 0.63. The genetic distance coefficients were in the range of 0.112–0.627. Cluster analysis revealed that the 27 lines and three cultivars could be divided into two main groups. No polyploidy was detected within any vetch lines tested while significant (P< 0.0001) nuclear DNA content differences were determined. The present study revealed that fast and accurate fingerprinting analysis could be done using SRAP and ISSR markers, which indicated existing significant variation among common vetch lines and cultivars.

Wild relatives of crop species are known to be sources of genetic diversity that can be used in crop improvement. However, they have not always been studied adequately for the variation that may exist within them, for traits which may have important implications from an evolutionary point of view and their use in breeding programmes. In the present study, a wild groundnut species, Arachis stenosperma, has been studied for variation between accessions collected from different sites in Brazil for morphological and certain nutritional traits, and for disease resistance. Multivariate analysis of 23 characters grouped 18 accessions into two clusters, while one accession, ICG 14927, was distinct from these. However, in protein profile they all appear identical. Hence, the variation appears to have arisen in response to the climatic conditions of their habitat, which has implications for use of these accessions in breeding programmes. The variation in these traits could not be associated with any phytogeographical regions. The dispersal of this species from its centre of origin and diversity to other parts of Brazil appears to be recent and without any identifiable selection pressures having operated.

Germplasm characterization is essential to estimate variation and identify desirable genotypes for crop improvement. The current study was conducted on eight qualitative and 14 quantitative traits related to growth and floral attributes for characterization and grouping of 54 chrysanthemum genotypes. Wide variability was observed among most of the traits and principal component analysis revealed that the first two principal components explained most of the existing variation (>98%) in germplasm. Genotypic coefficient of variation exhibited a wide range from 9.41% (ratio of leaf length/width) to 105.99% (corolla tube length of ray florets), while phenotypic coefficient of variation varied from 10.49% (ratio of leaf length/width) to 106.38% (corolla tube length of ray florets). Broad sense heritability estimates were higher (>96%) for most of the characters, except for traits such as ratio of leaf length/width and peduncle thickness. Forty-four pair-wise inter-trait combinations showed positive genotypic and phenotypic correlations for 91 possible combinations. D2 analysis revealed that genotypes of clusters I and IV to be highly distinct, and hybridization between them might have better chance to obtain desirable types. D2 analysis confirmed that the cultivars in cluster IV namely, Red D Spoon, Tokyo Soldier, Yellow Reflex and hierarchical clustering showed that the cultivar Tokyo Soldier to be highly diverse. It is recommended to use the above genotypes in crossing programme for obtaining better progenies.

Only a little information is available on the genetic association of basic within-boll yield components of segregating populations. A total of 25 genotypes were evaluated for genetic diversity using SSR markers in 2012; of these, eight diverse genotypes were selected to attempt the generation of five crosses. From the progeny of these five crosses, five F3 populations were developed. Data for within-boll yield components were recorded by taking 30 observations (one observation average of five bolls) from each population, and analysed for genotypic and phenotypic correlations followed by the path coefficient analysis from the genotypic correlation. The highest genotypic correlation was observed between seed cotton yield per locule and number of seeds per boll (ranging from 0.654 to 0.972 for different crosses). Except number of seeds per locule and lint percentage, all the other within-boll yield components had a highly significant positive correlation with seed cotton yield, whereas the former two had a negative correlation. Path coefficient analysis revealed that number of seeds per boll had a maximum direct effect on yield (ranging from 0.776 to 0.895 for different crosses), and also had a relatively high magnitude of the indirect effect via other traits. Differences were observed in the magnitude of correlation coefficients and direct/indirect effects for different populations, but the direction of genetic association always remained the same. The present study showed that number of locules per boll, seed cotton yield per locule, number of seeds per boll and seed cotton yield per boll can be used as efficient selection criteria for the improvement in seed cotton yield.

Sweet cherries can be grafted on a wide range of rootstocks belonging to Prunus avium, Prunus cerasus, Prunus mahaleb, Prunus angustifolia or hybrids of different Prunus species. Identification of Prunus rootstocks using morphological traits is almost impossible particularly during the dormant season. However, molecular analysis carried out on actively growing shoot tips, leaves or dormant buds provides good opportunity to reliably distinguish rootstocks. In this study, DNA was extracted from the leaves of a total of 184 sweet cherry rootstock candidates belonging to P. avium L., P. cerasus L., P. mahaleb L. and P. angustifolia L. previously selected from the north-western part of Turkey. The rootstock candidates were tested with ten simple sequence repeat (SSR) primers, developed for the Prunus genus. The primers successfully identified all rootstock candidates. The results showed that the number of alleles per locus ranged from 10 (UDAp-401, UCD-CH21 and CPSCT010) to 20 (UCD-CH31) with an average of 13.3 alleles per locus, indicating that the SSRs were highly informative. Unweighted Pair-Group Method with Arithmetic mean analysis demonstrated that P. avium accessions are closely related to P. cerasus. The reference rootstocks were clustered with their associated botanical species.