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Association mapping (AM), an alternative method of quantitative trait loci (QTL) discovery, exploits historic linkage disequilibrium (LD) present in natural populations. AM is effective in self-pollinated crops such as Dolichos bean as LD extends over longer genomic distance driven-by low rate of recombination and thereby requiring fewer markers for exploring marker-traits associations. A core set of Dolichos bean germplasm consisting of 64 accessions was evaluated for nine quantitative traits (QTs) during 2014 and 2015 rainy seasons and genotyped using 234 simple sequence repeats (SSR) markers. Substantial diversity was observed among the core set accessions at loci controlling QTs and 95 of the 234 SSR markers were found polymorphic. The structure analysis and low magnitude of fixation indices suggested weak population structure, which in-turn indicated the low possibility of false discovery rates in the marker-QTs association. The marker allele's scores were regressed onto phenotypes at nine QTs following general linear model and mixed linear model for exploring marker-QTs associations. Significantly higher number of SSR markers was found associated with genomic regions controlling nine QTs. A few of the markers such as KT Dolichos (KTD) 200 for days to 50% flowering, KTD 273 for fresh pod yield per plant and KTD 130 for fresh pods per plant explained ≥10% of the trait variations. The study could also identify a few SSR markers such as KTD 273, KTD 271 and KTD 130 linked to multiple traits. These linked SSR markers are suggested for validation for their use in marker-assisted Dolichos bean improvement programmes.
Seedling vigour is an important indicator of crop establishment, subsequent crop growth and yield. Initial seedling vigour is most vital in case of water-limited conditions and in environments where the crop is exposed to different stresses at the early growth stage. Wild and weedy species are well known for their vigour and survival in adverse environmental conditions. Seedling vigour traits of backcross introgression lines (BILs) derived from Swarna × Oryza nivara IRGC81848(S) (accession from Uttar Pradesh, India) and IRGC81832 (K) (accession from Bihar, India) were studied in wet (Kharif) and dry (Rabi) seasons. Seedling vigour was estimated in terms of plant height and tiller number at 30 and 60 d after transplanting under field conditions. In both the seasons, 148S showed highest seedling vigour for plant height. The highest number of tillers were produced by 7K in Kharif and 248S in Rabi season. 75S showed the highest percentage increase in tiller number consistently. High yielding BILs 166S, 14S and 148S showed higher seedling vigour indices compared with checks Tulasi and Sahbhagidhan. Seedling vigour was also evaluated using paper roll method and shoot length, root length and dry weight were used to estimate vigour index. Season-wise association studies were conducted to determine the relative contribution of seedling vigour to yield traits. Seedling vigour was significantly correlated with yield traits. Markers RM217 and RM253 on chromosome 6 differentiated lines with high seedling vigour from those with low seedling vigour and have the potential for use in marker-assisted breeding.
The U genome of Aegilops umbellulata is an important basic genome of genus Aegilops. Direct gene transfer from Ae. umbellulata into wheat is feasible but not easy. Triticum turgidum–Ae. umbellulata amphidiploids can act as bridges to circumvent obstacles involving direct gene transfer. Seven T. turgidum–Ae. umbellulata amphidiploids were produced via unreduced gametes for spontaneous doubling of chromosomes of triploid T. turgidum–Ae. umbellulata F1 hybrid plants. Seven pairs of U chromosomes of Ae. umbellulata were distinguished by fluorescence in situ hybridization (FISH) probes pSc119.2/(AAC)5 and pTa71. Polymorphic FISH signals were detected in three (1U, 6U and 7U) of seven U chromosomes of four Ae. umbellulata accessions. The chromosomes of the tetraploid wheat parents could be differentiated by probes pSc119.2 and pTa535, and identical FISH signals were observed among the three accessions. All the parental chromosomes of the amphidiploids could be precisely identified by probe combinations pSc119.2/pTa535 and pTa71/(AAC)5. The T. turgidum–Ae. umbellulata amphidiploids possess valuable traits for wheat improvement, such as strong tillering ability, stripe rust resistance and seed size-related traits. These materials can be used as media in gene transfers from Ae. umbellulata into wheat.
Soil salinity is a major limitation to legume production in many areas of the world. Identification of the genetic source of salt tolerance is critical in soybean breeding for improving soybean production in salt-affected regions. Vietnam has unique sources of soybean germplasm and varieties are grown in the area where exposure to salinity is frequent. However, there is little research on the identification of salt tolerant sources in the Vietnamese gene pool. The present study compared 18 Vietnamese soybean cultivars for their differences in salt tolerance. Under a range of NaCl stress from 0 to 200 mM NaCl, there was a large variation in salt tolerance among the 18 soybean lines evaluated. The soybean accession PI 675847 A (Vietnamese variety DT2008), was identified as a useful source of salt tolerance. During vegetative growth, PI 675847 A had lower leaf scorch scores, higher cell membrane stability, better photosynthesis and biomass accumulation under NaCl stress than the other 17 strains evaluated. In addition, PI 675847 A maintained better growth and seed yield in salt-affected soils compared with the sensitive lines. Analyses of ion contents in plant leaves under saline conditions showed that PI 675847 A was able to limit uptake and transport of Na+ and Cl−. Because of its higher productivity under saline conditions, PI 675847 A will be a useful germplasm source in soybean improvement programs for salt tolerance.
Lentil is now an integral part of prairie cropping systems. Climate forecasts point to variable and increased drought frequency, putting lentil production in jeopardy. Future lentil genotypes will require root systems that can extract more water under drought conditions. This study focuses on root diameter and root tip number, traits known to play an important role in water uptake during drought. We compared the total root length (TRL) in three soil horizons of both wild and cultivated lentil genotypes for three root diameter classes when plants were grown under moderate or severe drought, and when re-watered after exposure to moderate drought conditions. Our study demonstrates that roots of both wild and cultivated lentil genotypes can be categorized into very fine, fine and small diameter classes. Some wild lentil genotypes had significantly higher TRL in the B and C soil horizons when grown under severe or moderate drought and therefore, could act as resources for the transfer of root traits to cultivated lentil genotypes. Further evaluations focused on the root systems of interspecific recombinant inbred lines under drought conditions will be required to determine whether these traits are heritable.
The aims of the paper are to characterize the ornamental bedding behaviour of selected Glandularia materials, to evaluate breeder and public preferences (PP) of new potential ornamental plants to be introduced in the market and to obtain a ranking with the best-selected materials. After hybrids characterizations through different traits of ornamental interest, a survey was conducted to identify the breeder and PP separately but also with an integrated index. The indices were applied to systematize bedding data considering breeder and public aesthetic preferences using persistent (12-months plants) and new (3-months plants) materials. Similarities were found in the breeder and PP for new materials. The perception of a similar aesthetic value by the breeder and the public was reflected in the scores assigned to Glandularia hybrids materials. For persistent materials, breeder and public perceptions presented some differences that are interesting to be considered at the moment to introduce new ornamental plants into the market.
Eight yam species (Dioscorea spp.) represented by 522 accessions (landraces and hybrids) were analysed for the individual sugars, catechins, phenolic acids and saponins contents of their tuber flours. Maltose, sucrose, glucose and fructose were quantified. Reducing sugars mean values were highly variable within species and ranged from 0.16%dry weight (DW) (SD ± 0.12) in D. dumetorum to 3.15%DW (±2.49) in D. esculenta. Maltose was detected only in D. esculenta. Chlorogenic acid, gallic acid and other phenolic acids ranged from 4.33 mg/g DW in D. bulbifera to 4.87 mg/g in D. alata and 9.55 mg/g in D. nummularia but were not detected in other species. Catechins (epicatechin and catechin) were highest in D. bulbifera bulbils (25.18 mg/g) and tubers (6.96 mg/g), and lowest in D. esculenta (0.32 mg/g). Their content is significantly correlated with dark flour colour and they most likely contribute to the oxidation of tuber flesh. Saponins (dioscin and gracillin) were quantified in only two species: D. cayenensis (5.94 mg/g, SD ± 3.78) and D. esculenta (3.74 mg/g, SD ± 3.72). Varietal selection may tend to reduce sugars levels and increase secondary metabolites with bioactive properties. HP-TLC is a suitable technique for the rapid quantification of compounds related to yam tuber flour quality.
Grewia tenax locally known as ‘Gangerun’, is an important multipurpose underutilized shrub and potentially threaten species of the Thar Desert of India. Owing to its importance, naturally available germplasm was collected and evaluated for its sustainable utilization in future. Data on individual mother plant, seed characters and soil profile were investigated. Habitat occurrence of G. tenax was found in patches with dominant association of Euphorbia caducifolia across the four districts of western Rajasthan. Individual plant on unprotected area portrayed far lower average height (0.95 m) and canopy area (1.75 m2) than protected area (2.63 m and 13.89 m2) signifying level of browsing pressure on this species in Jaisalmer. Soil samples belonging to Pali region have high organic carbon and low electrical conductivity content than Jaisalmer and Jodhpur. The statistical analysis of seed characters revealed the presence of high coefficient of variation (%) in 100-seed weight (HSW; 27.36) followed by seed length (SL; 8.06) and least in seed breadth (SB; 5.85). The range and mean values of HSW, SL, SB and length:breadth ratio (LBR) were (2.02–7.00 and 3.34 g), (4.36–6.15 and 5.36 mm), (3.73–4.68 and 4.25 mm) and (1.11–1.44 and 1.27), respectively. Significantly positive correlation was observed between SL and LBR (0.73) followed by HSW and SL (0.66). Along with these findings, its economic importance, utilization and conservation are detailed in this paper as to hasten further research on its various aspects for its successful conservation and utilization.
Sorghum is a staple food crop in Niger and its production is constrained by sorghum midge and the use of low yielding, local sorghum varieties. To improve sorghum productivity, it is crucial to provide farmers with high yielding sorghum cultivars that are resistant to midge. We evaluated 282 genotypes in four environments of Niger Republic. Alpha (0.1) lattice with two replications was the experimental design. Genotype and genotype by environment (GGE) biplot analysis was used to study grain yield (GY) stability and G × E interactions. The results revealed that two distinct mega environments were present. Genotype L232 was the best genotype for GY in the first planting date at Konni and the first and second planting dates (PDs) at Maradi. Genotype L17 was the best for GY in the second PD at Konni. The second PD at Konni was the most discriminating environment while the first PD at Konni is suitable for selecting widely adapted genotypes for GY.
Thin pericarp is one of crucial selection criteria for high-tender waxy corn hybrid development. A pericarp thickness of 2414 maize landrace accessions including 87 public waxy inbred lines was investigated to select accessions with thin pericarp and to broaden genetic diversity among waxy corn cultivars. Observed pericarp thickness of the 2414 accessions ranged from 16.0 ± 1.56 to 139.2 ± 39.55 µm with the average of 47.7 ± 13.15 µm. More than half of the accessions were below the suggested thickness of <50 µm for high-tender waxy corn hybrid development. Large sample size resulted in significant differences among endosperm types and among collection provinces. This, however, may not translate into considerable difference in tenderness since most averages of different types and collection provinces were <50 µm. Positive correlation (r = 0.55) between the average and standard deviation of pericarp thickness implied that more samples are needed to achieve same level of precision when it comes to selection for thick pericarp than that for thin pericarp. Top 10% thin-pericarped waxy landrace accessions were intercrossed to form a new waxy corn population from this result.
A systematic method for determining colour descriptor states using image analysis is proposed using pili (Canarium ovatum) as a model. Kernel images of 52 pili accessions from the core collection of the Institute of Crop Science and National Plant Genetic Resources Laboratory, University of the Philippines Los Baños were captured using a calibrated VideometerLab 3 setup. Colour descriptor states were derived from the average International Commission on Illumination lightness (L*), green–red (a*) and blue–yellow (b*) colour component values. Cluster analysis and subsequent colour-parameter averaging per cluster were performed to produce representative colour values of descriptor states. The Euclidian distance (Delta E) of 3.5 was used to cut the cluster into readily distinguishable colour differences resulting to three descriptor states – light brown, brown and dark brown. Continuous colour variation of brown colour was observed indicating a possible quantitative nature of the trait. The use of delta E in elucidating the descriptor lists served as a gauge in successfully identifying distinguishable variations between colours. The method described can be applied to the elucidation of colour descriptor states of all parts of the plant of all crop species.
Licorice (Glycyrrhiza glabra) is an important medicinal herb and has long been used in traditional medicine for the treatment of several diseases worldwide. Understanding the genetic diversity within Glycyrrhiza species is important for the efficient conservation of these medicinal herbs. In this study, we have developed 20 polymorphic chloroplast microsatellite (cpSSR) markers using the chloroplast genome of G. lepidota. The cpSSR markers were tested on a total of 27 Glycyrrhiza individual plants. The number of alleles per locus ranged from two to eight among the Glycyrrhiza accessions. Overall, the Shannon index (I) for each cpSSR ranged from 0.315 to 1.694, the diversity indices (h) were 0.140–0.793 and the unbiased diversity indices (uh) were 0.145–0.825. In addition, the cpSSR markers were successfully divided and classified the 27 Glycyrrhiza individuals into four groups. The cpSSR markers developed in this study could be used in the assessment of genetic diversity and rapid identification of Glycyrrhiza species.