Genetic variability is the fundamental requirement of any crop breeding program to develop superior cultivars. The objective of this study was to estimate the genetic variability and find out the correlation among the different quantitative traits of rainfed early lowland rice. The experiment was conducted consecutively two years during 2015 and 2016 in wet season across the four different locations in Regional Agricultural Research Station, Khajura, National Wheat Research Program, Bhairahawa, National Maize Research Program, Rampur, and National Rice Research Program, Hardinath, along the Terai region of Nepal representing subtropical agroclimate. Seven genotypes including Hardinath-1 as standard check variety were evaluated in the randomized complete block design with three replications. Various quantitative traits were measured to investigate the variability and correlation coefficients. All the genotypes and locations showed significant variations for all the traits considered. Genotypic coefficient of variation was lower than phenotypic coefficient of variation for all traits studied. The magnitudes of genotypic coefficient of variations were relatively higher for grain yield, 1000-grain weight, and days to heading. The highest broad sense heritability of 94% was recorded in days to maturity and the lowest heritability of 16% was observed in plant height. Positive and highly significant correlations were found both in genotypic and phenotypic levels between days to heading and days to maturity (rg=0.9999 ⁎⁎, rp=0.997 ⁎⁎), days to heading and grain yield (rg =0.9999 ⁎⁎, rp= 0.9276 ⁎⁎), and days to maturity and grain yield (rg =0.9796 ⁎⁎, rp=0.9174 ⁎⁎). However, negative and highly significant genetic correlation was observed between plant height and 1000-grain weight (rg = -0.9999 ⁎⁎). Thus results indicated that days to heading, days to maturity, grain yield, 1000-grain weight demonstrating higher heritability and remarkable genetic advance could be considered the most appropriate traits for improvement and selection of trait to achieve stable and high yielding early rice genotypes under rainfed environments.

The genetic basis of seed germination and seedling vigor is largely unknown in Brassica species. We performed a study to evaluate the genetic basis of these important traits in a B. rapa doubled haploid population from a cross of a yellow-seeded oil-type yellow sarson and a black-seeded vegetable-type pak choi. We identified 26 QTL regions across all 10 linkage groups for traits related to seed weight, seed germination and seedling vigor under non-stress and salt stress conditions illustrating the polygenic nature of these traits. QTLs for multiple traits co-localized and we identified eight hotspots for quantitative trait loci (QTL) of seed weight, seed germination, and root and shoot lengths. A QTL hotspot for seed germination on A02 mapped at the B. rapa Flowering Locus C (BrFLC2). Another hotspot on A05 with salt stress specific QTLs co-located with the B. rapa Fatty acid desaturase 2 (BrFAD2) locus. Epistatic interactions were observed between QTL hotspots for seed germination on A02 and A10 and with a salt tolerance QTL on A05. These results contribute to the understanding of the genetics of seed quality and seeding vigor in B. rapa and can offer tools for Brassica breeding.

Genetic variability is the fundamental requirement of any crop breeding program to develop superior cultivars. The objective of this study was to estimate the genetic variability and find out the correlation among the different quantitative traits of rainfed early lowland rice. The experiment was conducted consecutively two years during 2015 and 2016 in wet season across the four different locations in Regional Agricultural Research Station, Khajura, National Wheat Research Program, Bhairahawa, National Maize Research Program, Rampur and National Rice Research Program, Hardinath along the Terai region of Nepal representing sub-tropical agroclimate. Seven genotypes including Hardinath-1 as standard check variety were evaluated in the randomized complete block design with three replications. Various quantitative traits were measured to investigate the variability and correlation coefficients. All the genotypes and locations showed significant variations for all the traits considered. Genotypic coefficient of variation was lower than phenotypic coefficient of variation for all traits studied. The magnitudes of genotypic coefficient of variations were relatively higher for grain yield, 1000-grain weight and days to heading. The highest broad sense heritability of 94% was recorded in days to maturity and the lowest heritability of 16% was observed in plant height. Positive and highly significant correlations were found both in genotypic and phenotypic levels between days to heading and days to maturity (rg=0.9999**, rp=0.997**), days to heading and grain yield (rg =0.9999**, rp= 0.9276**), days to maturity and grain yield (rg =0.9796**, rp=0.9174**).However, negative and highly significant genetic correlation was observed between plant height and 1000 grain weight (rg = -0.9999**). Thus results indicated that days to heading, days to maturity, grain yield, 1000 grain weight demonstrated higher heritability and remarkable genetic advance could be considered for the most appropriate traits for improvement and selection of trait to achieve stable and high yielding early rice genotypes under rainfed environments.

Seven tomato varieties, Ahmita, BL-410, Ceres, Dalila, Makish, Srijana and Winsari were evaluated for physicochemical properties and fruit yield under plastic house condition during rainy seasons of two consecutive years 2012 and 2013 at the Regional Agriculture Research Station, Lumle, Kaski . The experiment was laid out in a complete randomized block design with four replications. The physicochemical analyses revealed that BL-410 had the highest total soluble solid (5.22 oBx) while Srijana had the highest tritrable acidity (0.903%) and vitamic C content (32.32 mg/100 g). It showed that Srijana was the most useful variety from nutritional perspective. BL-410 took least time to flowering (22.00 days), fruiting (28.00 days) and first harvesting (72.00 days) after transplanting. Ahmita produced maximum number of fruits per cluster (8.43). Ceres produced largest size (122.0 g) fruit while Winsari measured the tallest plant (120.5). Winsari produced highest marketable yield (105.8 t ha^-1). Thus, it has been recommended for commercial production. Srijana, which has highest nutritional value needs to be promoted with increasing its productivity.DOI: http://dx.doi.org/njst.v15i2.12106 Nepal Journal of Science and Technology Vol. 15, No.2 (2014) 17-22