Information on the availability of genetic variability and mode of gene action are critically important for choosing effective breeding methods that result in appreciable improvement in performance under drought stress. An investigation in rice (Oryza sativa L.) was carried out subjecting six 'lines' and 15 'testers' crossed in a line × tester mating design and the 90 hybrids along with 21 parents were tested for gene action, combining ability for 19 traits under aerobic condition. Three 'lines' viz., IR79128A (L 1), IR79156A (L 2) and IR70369A (L 4) and three 'testers' viz., IR7925A-428-2-1-1R (T 4), KMP-148 (T 12) and BI-33 (T 15) were identified as the best general combiners. The genotype IR70369A is suggested for conversion to cytoplasmic male sterility with suitable male sterile source. The parents MAS-26, IR 7925A-428-2-1-1R and KMP-105 are recommended for testing their restorability with suitable CMS source.

Abstract. The Solanaceae family includes plants of high economic and medicinal value. Information on endorhizal associations in Solanaceae is limited. We investigated arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in 20 solanaceous plant species (7 genera) taken from one or more sites, measuring the percentage of root length colonized in plants having different AM and DSE fungal structures. Root samples of all the plant species examined had AM fungal structures, and DSE fungal colonization was found in 80% of the plant species. Total AM and DSE fungal colonization and root length of plants with different fungal structures varied significantly between species. Significant between-site variation was found for root length in plants with fungal structures in Lycopersicon esculentum Mill., Capsicum annuum L., Datura metel L., Solanum melongena L., S. nigrum L., S. trilobatum L. and S. torvum SW. AM morphology was predominantly intermediate-type (60%), followed by Paris-type (30%). Solanum melongena and S. nigrum at different sites had Paris-type or intermediate AM morphology. DSE fungal colonization also exhibited significant between-site variation in Capsicum frutescens, C. annum, Datura metel, Solanum melongena, S. trilobatum and S. nigrum. We found a significant negative correlation between AM and DSE fungal colonization.

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Sufficient genetic variability was recorded among the 90 hybrids and 21 parents of rice genotypes under aerobic condition. Genotypic and phenotypic correlations were ascertained for grain yield and its components. The results revealed that the traits productive tillers per plant, panicle length, spikelet fertility, harvest index, proline content, SPAD chlorophyll meter reading, chlorophyll stability index, relative water content and dry root weight as they expressed significant and positive correlation with single plant yield and also positive inter correlations among themselves. Therefore, selection for any one of the above characters would bring in simultaneous improvement of other characters and ultimately improving the grain yield.