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Seed and seedling vigour is an aspect of seed quality which affects field establishment and performance. Low maize yields have been reported to be affected by several factors in which poor quality seed with low seed and seedling vigour. Information is scarce on seed and seedling vigour in maize inbred lines developed for tropical environments. Fifteen genotypes of tropical maize (Zea mays L.) inbred lines were evaluated to determine the level of differences in seed and seedling vigour traits, and extent of relationships among traits and their heritability. A substantial amount of genetic variability was found, which suggested that most of the traits under study could be improved through selection and utilized in breeding programs. Positive and significant interrelationship among seed germination and seedling traits and a positive correlation between seed germination and seed vigour and field emergence showed that these could be given due consideration in crop improvement for seed and seedling vigour. High genotypic coefficient of variation, heritability and genetic advance were obtained for seed germination, seed emergence, shoot length and seedling vigour index I and II, revealing the possibility of improvement in these characters through direct selection. The principal component analysis (PCA) identified seed emergence, shoot length, seedling vigour index I and II and tetrazolium vigour as characters that contributed greatly to variation in seed vigour in the maize inbred lines. Cluster analysis partitioned the genotypes into two groups, with group I consisting of seven genotypes and group II comprised the other eight genotypes, which suggested that hybridization between the two groups could lead to high level of heterosis. Genotype V 5 had superior seedling vigour traits compared to other genotypes. Seedling emergence, shoot length, seedling vigour index I, seedling vigour index II and tetrazolium vigour are effective characters for good seedling vigour traits in maize inbred lines investigated.

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The experiment was aimed at assessing the response of 30 rice genotypes to different levels of salinity using NaCl concentration as salt stress at early seedling stage under hydroponic conditions. The experiment was replicated three times in a Completely Randomized Design for two years. The 30 rice genotypes evaluated for root length, fresh root weight, dry root weight, shoot length, fresh shoot weight, dry shoot weight, seedling biomass and shoot/root length ratio. The four salinity treatments/levels (0, 4, 6 and 12 dS/m) significantly affected the response of the 30 rice genotypes for all the traits evaluated. The interaction between salinity treatments and the genotypes was significant for all traits except fresh root weight, shoot length and dry shoot weight. The genotypic response revealed reduction in performance as the salinity level increases for all the traits, 10 genotypes were tolerant at all salinity levels. The most affected seedling trait due to salinity stress was seedling biomass at 6 dS/m (54.84%) and was expressed by genotype IR29 (susceptible check), followed by ROK 24 at 12 dS/m (54.43%). Eight rice genotypes; CK73, ITA212 (FARO 35), ITA222 (FARO 36), OG0315, OG250315, OW0315, TOG 5681 and Pokkali (Tolerant Check) were classified highly tolerant by both Stress Tolerance Index (SST) and Stress Susceptible Index (SSI), while FARO 61 (NERICA L -34) and IR72 were moderately tolerant. These rice genotypes have good potentials for further salt tolerance breeding.

Grain Amaranths are important nutritional vegetables in the world for their grains and leaves. Twelve grain Amaranth accessions were evaluated for their performances using randomized complete block design with 3 replications in the cropping seasons of 2016 and 2017 to measure variability, Classify the accessions and select outstanding genotypes. Analysis of Variance and accessions performances revealed significant variability among the grain Amaranths. Phenotypic variances were higher in magnitude than genotypic variance for all the traits studied. The high genetic advance was obtained for all the characters except 1000 grain weight (23.61). The genotypic coefficients of variations were lower than the phenotypic coefficient of variations. Heritability ranged from 41.08% for grain yield/plot to 62.18% for plant height at flowering. Grain yield was positive and highly significantly correlated with 1000 grain weight, leaf area but significantly correlated only with leaf length and leaf width. The Principal Component Analysis (PCA) revealed four main components of variations representing 78.06% of the total variability among the 12-grain amaranth accessions. The PCA identified all the 12 traits as strongly correlated with the three principal components. PC1 is well-correlated with plant height at flowering, stem girth, a number of leaves, plant height at maturity, leaf width, leaf length, leaf area and petiole length. The bi-plot analysis classified the accession NG/AA/03/11/010, NGB 01259, and NGB 0127 as having good leaf yield and desired leaf traits, Accession NHGB/09/108, NG/AO/08/04 and NGB 01261 were grouped as better grain yield with good yield attributes, while accession NGB 01234, NHGB 09/09 and NHAC3 are good dual-purpose accessions having good grain and leaf yield.