Plant Genetic Resources最新文献

In an effort to control anthracnose disease, one of the major problems that has been faced by farmers, 14 chilli hybrids and their parents were screened phenotypically using the fruit inoculation method under laboratory conditions. Genotypic screening of 14 chilli hybrids and their parents was done by the identified polymorphic markers, HpmsE 051 and HpmsE 082. Based on the phenotypic and genotypic data, chilli hybrids, H1, H2, H3, H4, H6, H7, H8, H9, H11 and H12 were identified as resistant chilli hybrids against anthracnose disease caused by the C. truncatum. Molecular markers, HpmsE 051 and HpmsE 082 could be utilized as polymorphic markers to isolate resistant genotypes against C. truncatum.

The patterns and extent of genetic variation among 56 cashew germplasm with respect to 32 qualitative and 33 quantitative traits were evaluated for two successive years in the present study. Additionally, maturase K gene-based genetic diversity among those breeding materials was also assessed. The cashew hybrids were developed from five crosses (local parent × 2/9 Dicherla; H-2/15 × red hazari; WBDC-V × JGM-1; BLA-39-4 × H-2/15 and H-2/15 × yellow hazari) involving eight parents of Indian cashew. Different genotype groups (parents and their hybrids) showed significant variation in both the years of assessment based on quantitative characters. The highest Shannon–Weaver diversity (H′) was obtained for the colour of the young leaf (0.96), possibly indicating differential exposure to sunlight, mixing of various pigments and another set of chemicals such as phenolics, carotenoids, etc. in trees. From correlation studies, canopy spread, tree spread, nuts/m2 and nuts/panicle were found to be significantly and positively correlated with nut yield. In the year 2021, nuts/m2, area and tree height were the significant explanatory variables that explained 80% of the variation in the yield, whereas in 2022, nuts/m2, tree area, nuts/panicle, kernel weight, shell thickness, inflorescence breadth and sex ratio explained 86% of the variation. Principal component analysis indicated that the genotypes under study are diverse enough to be exploited for the future cashew improvement programmes.

Melon is one of the important cucurbitaceous crops being cultivated widely in India and known for its delicious fruits. Crop is threatened by different biotic stresses including nematodes, fungi and viruses. The use of host resistance is the most economical, eco-compatible and long-lasting strategy to combat plant diseases. Keeping in mind this objective, 64 melon genotypes were screened against the prevalent Meloidogyne incognita, Fusarium oxysporum and tomato leaf curl Palampur virus (ToLCPalV) individually as well as with combined inoculations under artificial conditions. Out of 64 genotypes, three genotypes, MCPS, SM2012-1 and WM11 were found moderately resistant to M. incognita, nine genotypes (MM-KP15103, MM327, MM121103, KP4HM15, MM Sel.-103, SM2013-2, SM2012-1, SM2013-9 and WM11) recorded a resistant reaction against Fusarium wilt while four genotypes, WM11, SM2012-1, SM2013-9 and SM2013-2 exhibited a highly resistant reaction against ToLCPalV. A dendrogram constructed based on the resistance response of all the genotypes divided the genotypes into two groups and all resistant genotypes (MM1804, MM120103, SM2012-1, MM121103, SM2013-2, SM2013-9, WM11 and MM Sel.103) clustered in group II. The resistant genotypes when subjected to simultaneous inoculations of all three pathogens showed an increase in disease severity for each pathogen which negatively altered the resistance response of different genotypes. However, the genotypes SM2012-1, SM2013-9, SM2013-2 and WM-11 showing multiple disease resistance exhibited a good level of resistance even after combined inoculations of three pathogens. This study is the first to our knowledge identifying multiple disease resistance against root-knot nematode, Fusarium wilt and tomato leaf curl Palampur virus in muskmelon.

Tetraploid wheat species from Ethiopia hold ample genetic variation, which could provide a source for improvement of wheat. A total of 196 Ethiopian tetraploid wheat (Triticum turgidum spp.) accessions, including 174 landraces and 22 improved cultivars, were evaluated at Sinana and Debrezeit to assess morphological variation, genetic advance, heritability and correlation based on 11 phenotypic traits. Except for spike length, highly significant variation (P < 0.001) among genotypes for all traits was observed. The observed mean and range values of the phenotypic traits revealed high variability in the accessions. Phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) values were high for grain yield, biomass yield and harvest index. Seed yield showed highly significant (P < 0.001) negative correlation with days to booting and days to maturity and positive correlation with all traits. The estimates of heritability (H2) for grain yield and the number of spikelets per spike respectively ranged from 41.78 to 84.62%. The genetic advance as a percentage of mean was low for the number of seeds per spikelet, days to booting and days to maturity; intermediate for plant height, thousand kernel weight and spike length and high for the number of spikelets per spike, the number of effective tillers per plant, grain yield, biomass yield and harvest index, respectively. The number of spikelets per spike gave a high value of genetic advance and heritability implying high genetic gain from its selection.

The Lecythidaceae family tree, Couroupita guianensis Aubl, popularly known as Nagpushpa, is a widely cultivated ornamental tree with several uses in traditional medicine. The tree is revered as highly sacred in Indian traditional culture due to its uniquely shaped, fragrant flowers. Considering the significance, we were prompted to carry out the metabolite and transcriptome analysis of Nagapushpa. The flower, petals, stamen, stem and leaf of C. guianensis were metabolically profiled, and it was discovered that the flower tissue contained the highest terpenoid reservoir. A number of terpenoid pathway transcripts were also found in the flower tissue after transcriptome profiling. KEGG pathway mapping was carried out to correlate transcript sequences with the biosynthesis of different types of terpenes. We were able to clone three full-length terpene synthase gene candidates, i.e. monoterpene ocimene synthase, diterpene ent-kaurene synthase and sesquiterpene farnesene synthase. The transcript expression of selected terpene synthase genes was also verified in flower tissue. These cloned sequences were used for in silico structural investigations and protein function prediction at the level of 3D structure. The data presented in this study provide a comprehensive resource for the metabolic and transcriptomic profiles of C. guianensis. The study paves the way towards the elucidation of terpene biosynthetic pathway in C. guianensis and heterologous production of useful terpenoids in the future.

The evolutionary relationship between domesticated Oryza species and their wild relatives in North East India is not well understood. To improve the understanding of the evolutionary relationship, this study investigates the genetic diversity of 68 indigenous rice landraces from North East India, ten O. rufipogon genotypes, and nine O. nivara genotypes using chloroplast variable repeat markers which, due to non-recombination and uniparental inheritance, enable better phylogenetic inference. Reference genotypes IR64 (indica) and Nipponbare (japonica) were included to characterize various phylogenetic clusters. Using distance-based hierarchical clustering, model-based structuring and principal component analysis, selected landraces from the three North Eastern Indian states of Assam, Manipur and Arunachal Pradesh were grouped into two phylogenetically different clusters that represented the IR64 and Nipponbare groupings. Interestingly, despite the fact that a cluster analysis combining North East landraces and wild relatives likewise produced two separate clusters (cluster I: Nipponbare, cluster II: IR64), the majority of the wild relatives were only clustered in the IR64 cluster. This suggests that the two distinct evolutionary histories of the rice landraces in North East India are distinguished by their genetic affinity for wild relatives and their variation in the indica and japonica pools. These results highlight chloroplast divergence influencing the genetic diversity of North East landraces with wild relatives. Further, these findings will enable in-depth studies on the functional significance of chloroplast diversity on trait adaptation in rice landraces.

Despite the increasing demand for diverse Centella asiatica (L.) Urb. species in Korea, studies on related topics are limited, with the majority of studies focusing on functional evaluations, rather than genetic diversity. Therefore, in this study, we explored the genetic diversity of C. asiatica, a valuable medicinal plant collected from six island regions in Korea, using genotyping-by-sequencing analysis. Specifically, we aimed to understand plant genetic variations, population structure and the potential for conservation and genetic improvement. The results indicated relatively high genetic diversity among the samples collected from the six island regions but low genetic differentiation among their populations. Two distinct genetic clusters were identified; however, even within these clusters, genetic differentiation was minimal. The lack of significant isolation-by-distance patterns and evidence of potential clonal spread suggested that some individuals that adapted to colder Korean conditions achieved dominance. This study highlights the importance of assessing the genetic diversity of native C. asiatica in Korea and explores the possibility of conducting follow-up studies to understand the phytochemical content and bioactivity variations among the individuals. This information can aid in the selection of superior resources and effective utilization of plant genetic resources for cultivar development and other applications.

Exploring the nutritional potential of underutilized legumes such as Dolichos bean (Lablab purpureus L.) is of great significance, particularly, in view of accomplishing the United Nation's Sustainable Development Goal number two, which emphasizes on improving food and nutrition security by 2030. A thorough understanding of genetic variability is crucial for developing biofortified cultivars of Dolichos bean. In this study, the Dolichos bean genotypes represented by pole and bush types (28 bush and 19 pole types) were assessed for genetic variability for Cu, Mn, Fe and Zn contents. Pole type genotypes had higher average contents for all micronutrients except manganese. Among micronutrients, Cu, Fe, Mn and Zn, content ranged from 10.10–19.95, 77.13–331.93, 22.78–46.40 and 42.03–102.85 mg kg−1 in pole type, and 8.2–18.5, 50.8–99.3, 25.65–53.25 and 37.15–63.25 mg kg−1 in bush type beans, respectively. Strong positive correlations between Cu, Fe and Zn concentrations occurred, which indicates the possibility of simultaneous improvement of these nutrients. Pod pigmentation was positively correlated with contents of Fe and Zn. There was an association of micronutrients with yield. The pole genotypes VRSEM-1000, VRDB-01 and VRSEM 109 and bush type genotypes VRBSEM-3, VRBSEM-35 and VRBSEM- 200 are good source of microelements and high yielders. Gene sources with enhanced nutrients may be used as cultivated forms or as input material for breeding nutritionally rich biofortified varieties of bean.

A total of 32 sweet potato genotypes were evaluated to assess the genetic diversity based on quantitative traits and molecular markers, as well as stability for yield and related traits. Wider variability was observed for the traits like vine length (181.2–501.3 cm), number of leaves/plant (103.0–414.0 cm), internodal length (3.20–14.80 cm), petiole length (6.5–21.3 cm), leaf length (8.50–14.5 cm), leaf breadth (8.20–15.30 cm), leaf area (42.50–115.62 cm2), tuber length (7.77–18.07 cm), tuber diameter (2.67–6.90 cm), tuber weight (65.60–192.09 g), tuber yield (7.77–28.87 t ha−1), dry matter (27.34–36.41%), total sugar (4.50–5.70%) and starch (18.50–29.92%) content. Desirable traits such as tuber yield, dry matter and starch content have shown high heritability (>60%) with moderate to high genetic advance. Under molecular analysis, a total of 232 alleles were observed from all 32 microsatellite markers, which ranged from 4 to 14 with an average of 7.77 alleles per locus. In the population, the average observed heterozygosity (0.51) was higher than the expected heterozygosity (0.49). The contribution of genotype, genotype by environment interaction to the total variations was found to be significant. Based on the multi-trait stability index (tuber length, tuber diameter, tuber weight and tuber yield), genotypes X-24, MLSPC-3, MLSPC-5, ARSPC-1 and TSP-12-12 were found to be most stable. Among them, the high-yielding and stable genotypes TSP-12-10 (26.0 t ha−1) and MLSPC-3 (23.9 t ha−1) can be promoted for commercial production or used as parental material in future crop improvement programmes.

Low level of resistance to major diseases such as ascochyta blight (AB), botrytis grey mould (BGM) and dry root rot (DRR) in the cultivated chickpea genepool necessitates harnessing wild Cicer species. Sixty-eight accessions belonging to eight annual wild Cicer species and seven chickpea cultivars were screened for AB, BGM and DRR under controlled environmental conditions over the years. Intra-accession variability was observed among wild Cicer accessions for each disease. Hence, progenies of single resistant plants were selected for further evaluations and the trait-specific genetic stocks (TGS) were developed for each disease after re-screening following the single seed descent method. For AB, a high level of resistance was identified in four accessions belonging to tertiary genepool species, ICC 17334 (Cicer judaicum), ICC 17302, ICC 17308 and ICC 20177 (C. bijugum). Nine accessions, ICC 17160, ICC 17264, ICC 17270, ICC 20170, ICC 20186, ICC 20225, ICC 20247, ICC 20251 and IG 72941 of primary (C. reticulatum) and one accession, ICC 20190 of secondary (C. echinospermum) genepool species were resistant to BGM whereas, four accessions, ICC 20187 (C. reticulatum) and ICC 20218, ICC 20244 and ICC 20257 (C. echinospermum) were resistant to DRR. Development and utilization of these TGS in chickpea pre-breeding will assist in developing disease-resistant chickpea cultivars with broad genetic base.