Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2, and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future.

An experiment was conducted at the Research farm of Regional Agricultural Research Station, BARI, Hathazari, Chittagong during Rabi season (December to April), 2009-2010 for estimation of genetic variability, genetic parameters and correlation coefficient among different yield components in a randomized block design with three replications. Thirty four groundnut genotypes were tested in the experiment. Highly significant variations were observed among the genotypes for all the characters studied. The highest genetic coefficient of variation was observed for karnel yield per hectare, followed by karnel yield per plant, branches per plant, immature and mature nuts per plant, 100 kernal weight and plant height. The highest heritability was observed in karnel yield per pant (95.08%), followed by karnel yield per hectare (94.38%), 100 kernal weight (87.01%), immature and mature nuts per plant (82.24%, 80.32%), branches per plant (79.54%) and 100 nut weight (78.98%), while high values of genetic advance were obtained in all the characters except days to maturity and days to 50% flowering. The seed yield per plant showed the highly significant and positive association with nut size, number of nuts per plant, karnel size and days to 50% flowering. The number of mature nuts per plant had high positive direct effect on seed yield per hectare followed by nut size, shelling percentage, days to 50% flowering and days to maturity. Therefore, branches per plant, plant height, nuts per plant, nut size, karnel size, days to 50% flowering, shelling percentage and days to maturity were identified to be the important characters which could be used in selection for yield. Keywords: Genetic variability; heritability; genetic advance; groundnut DOI: http://dx.doi.org/10.3329/agric.v9i1-2.9476 The Agriculturists 2011; 9(1&2): 29-36

Rust is the most devastating fungal disease in wheat. Three rust diseases, namely, leaf or brown rust caused by Puccinia triticina Eriks, stem or black rust caused by Puccinia graminis f. sp. tritici West, and stripe or yellow rust caused by Puccinia striiformis f. Tritici Eriks, are the most economically significant and common diseases among global wheat cultivars. Growing cultivars resistant to rust is the most sustainable, cost-effective and environmentally friendly approach for controlling rust diseases. To date, more than 187 rust resistance genes (80 leaf rust, 58 stem rust and 49 stripe rust) have been derived from diverse wheat or durum wheat cultivars and the related wild species using different molecular methods. This review provides a detailed discussion of the different aspects of rust resistance genes, their primitive sources, their distribution in global wheat cultivars and the importance of durable resistant varieties for controlling rust diseases. This information will serve as a foundation for plant breeders and geneticists to develop durable rust-resistant wheat varieties through marker-assisted breeding or gene pyramiding.