The purity of seeds can be identified from the traits inherited from their parental lines. Hence, contamination may occur at the crossing step due to unshared similarities with their parents. This research aims to measure the genetic purity of several genotypes obtained from crosses between upland and lowland rice through the banding pattern differences among the genotype samples by using Simple Sequence Repeats (SSR) markers. Taking the leaf samples was carried out at the experimental field, while the marker analysis was conducted in the Plant Biotechnology Laboratory. In this research, 8 (eight) genotypes obtained from crossing, comprising F1, F2, and BC1 along with 4 (four) of their parents from upland rice and lowland rice, were tested using 6 (six) drought-specific SSR primers of RM5, RM211, RM232, RM249, RM255, and RM258. The banding pattern of the electrophoresis results on the 12 rice genotypes showed clear, unsmeared quality. Based on the results of distance and genetic similarities, the 12 genotypes could be classified into 4 (four) clusters in the dendrogram. Cluster I consists of the
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Peanut (
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Salinity is the most significant constraint to wheat cultivation in the salinity-affected areas. Saline-prone soils can be brought under cultivation by the development of salt-tolerant lines through molecular breeding aided by diversity analysis and molecular screening. The study aimed to screen for salinity tolerance and elucidate the extent of diversity among 75 wheat varieties and accessions. This molecular analysis and detection used 21 linked SSR markers. The study identified 202 alleles in 75 genotypes of wheat, giving 9.6 alleles on an average for salt tolerance screening. The mean polymorphism information content (PIC) of 0.7599 and the Nei’s (1973) gene diversity of 0.7856 were recorded. The accessions possess higher gene diversity and PIC than the cultivars. The average genetic similarity matrix coefficient was 0.60 within the range of 0.19 and 1.00. Similarity indices based UPGMA cluster analysis separated the 75 germplasm into six clusters. Eight genotypes grouped in sub-cluster Ib together with the positive control BINA Gom-1. Therefore, these eight genotypes were identified as potential salt-tolerant by molecular analysis using SSR markers linked to salinity. The gene diversity estimated, and the germplasm identified as potential salt-tolerant are promising for use in wheat breeding to incorporate salt tolerance in novel cultivars by marker-assisted breeding.
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Maize is a major staple food and source of income for over 90% of the population in South Sudan however, average yield is very low (0.5-0.9 t/ha). Little research has been done on maize improvement in the country and farmers mainly depend on local and unimproved cultivars. Identification and release of adapted and high yielding hybrids may elevate average maize yield (t/ha) among the resource-poor farmers in the country. Improved maize hybrids from the region have not been tested under South Sudanese environments.
Objective
s of the study were to: (i) determine genotype by environment interactions among some regional maize genotypes; (ii) estimate genetic components and heritability for yield performances; and (iii) identify high yielding maize hybrids adapted to agroecologies of South Sudan. At least 48 maize genotypes including elite hybrids and open-pollinated varieties (OPV) adapted across sub-Saharan Africa and two local cultivars collected from local farmers in South Sudan were evaluated across five locations within greenbelt and ironstone plateau agro-ecologies over three years (2013-2015). Experiments were set up in a 12 × 4 alpha lattice design with 2 replications. Standard agronomic practices were followed and data recorded on yield traits and resistance to major diseases. Across locations and years analysis revealed significant differences among genotypes due to genotype and genotype × environment interactions (
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In salinity affected areas, variation in salinity level is the major cause of yield fluctuations in rice during the dry season (
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A two-year factorial arranged field experiment in randomized complete block design with three replications was carried out in 2014 and 2015 at Michael Okpara University of Agriculture Teaching and Research Farm, Umudike (latitude 05° 29′N; longitude 07° 33′E; altitude 122 m above sea level), Nigeria. The
objective
s were to assess growth and yield response of twenty newly released cowpea genotypes to different planting dates (July, August and September). Plant height, number of leaves/plant, number of branches/plant, shoot biomass, total dry matter, number of nodules/plant, weight of pod, number of seeds/pod, seed weight/pod and grain yield varied amongst the genotypes and across the different planting dates in both years. The association between grain yield and other variables analysed across both years was significant and positive except 100-seed weight and the phenological characters of the plant. Path coefficients analysis across two years indicated that seed weight/pod followed by number of branches/plant and number of seeds/pod had positive direct effect on grain yield of cowpea in contrast to characters that exhibited negative but direct effect on yield. The other traits had relatively negligible to low indirect effects that were positive through other component traits. The grain yield sequence of interaction between genotype and date of planting was in this order: IT06K-141 planted in July > IT11K-61-82 planted in September > IT99K-573-1-1 planted in August. IT06K-141 genotype was considered to be better endowed genetically while the mean across both years indicated August as appropriate planting date to ensure high and sustainable grain yield.
Identification and authentication of parentage are important for effective pear breeding. Within Korean pear cultivars discrepancies are often reported between parents and offspring in skin color of fruits and also in
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Perennial poor fruit-set and variability in tree yield are among major problems of cashew nut production. Thus, development of improved stable genotypes would be a sustainable strategy to address this perpetual problem in order to boost income and livelihood of many smallholder farmers of this important commodity crop. Here, we have applied additive main effect and multiplicative interaction (AMMI) and genotype, genotype by environment (GGE) biplot analysis to a 3-year multi-locational trial data on nine yield component characters of cashew to evaluate phenotypic stability across diverse environments. Variance analysis showed significant variability in the cashew genotypes and strong influence of genotype by environment (GxE) on tree yield as none of the genotypes was stable for any of the yield components across locations. GxE data showed that a substantial portion of the variation was explained by the genotype (highly heritable), accounting for between 10% and 87% of the variation, while the environment accounted for between 0.7% and 37%. Data showed significant higher values of interaction (GxE) than the respective values for environment, and were mostly captured and could be explained by the first principal component axis (IPCA 1) for all the yield component characters. There was an inverse relationship between stability and yield as the best three yielding genotypes (KT_26, IW_222 and IW_31) were found to be the most unstable. Among the yield component tested, hermaphrodite flowers per panicle, nuts per panicle, nuts per tree, nut weight, and tree fruiting efficiency were identified to be critical components for nut yield. Although there was wide variation between the three environments evaluated, the data effectively identified two mega-environments (ME), and two superior genotypes (IW_222 and KT_26) suitable for these two mega-environments. The GxE complex exposes the short-comings of broad recommendations of common agronomic-husbandry technologies across diverse cashew ecologies as each mega-environment would require specific adaptable technologies for optimal plant output. Above all, the data presented here underscore the importance of multi-locational evaluation of genotypes for varietal development in cashew.
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