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A field experiment was conducted using twenty three rice genotypes including three check varieties during the period from June to December, 2013, at the Agronomy Field Laboratory, Department of Agronomy, Bangladesh Agricultural University, Mymensingh to study genetic variability, heritability and genetic advance (GA) for yield and yield associated traits in rice. The experiment was laid down in a randomized complete block design with three replications. Plant height, number of filled grains per panicle, days to 50% flowering, thousand grain weight, grain width and grain yield showed relatively high genotypic co-efficient of variation (GCV) and phenotypic co-efficient of variation (PCV) estimates. The PCV were higher than GCV for all eight traits indicating that they all interacted with the environment to some extent. High heritability was obtained for grain width (88.54%), followed by days to 50% flowering (87.61%), thousand grain weight (81.96%), grain length (81.94%), days to maturity (81.81%) and number of filled grains per panicle (78.19%) which indicates high heritable portion of variation. High to medium estimates of heritability and genetic advance were obtained for number of filled grains per panicle (18.97), days to 50% flowering (11.89), days to maturity (12.16) indicating the roles of additive gene action and a good scope of selection using their phenotypic performance. Considering, all of these characters, filled gains per panicle and days to 50% flowering and maturity were important yield related traits and could be used for selection in rice breeding programs.Progressive Agriculture 26:26-31, 2015

The brassinosteroid pathway promotes a variety of physiological processes in plants and the brassinosteroid insensitive1-ethylmethane sulfonate suppressor (BES)/brassinazole-resistant (BZR) functions as one of its key regulators. We previously showed that the BES/BZR-type transcription factor TaBZR2 mediates the drought stress response in wheat (Triticum aestivum) by directly up-regulating the transcriptional activity of glutathione S-transferase 1 (TaGST1). However, the function of TaBZR2 in plants under biotic stresses is unknown. In this study, we found that transcript levels of TaBZR2 were up-regulated in response to inoculation with wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, Pst) and treatment with flg22 or an elicitor-like protein of Pst, Pst322. Wheat lines overexpressing TaBZR2 conferred increased resistance, whereas TaBZR2-RNAi lines exhibited decreased resistance to multiple races of Pst. TaBZR2 targeted the promoter of the chitinase gene TaCht20.2, activating its transcription. Knockdown of TaCht20.2 in wheat resulted in enhanced susceptibility to Pst, indicating the positive role of TaCht20.2 in wheat resistance. Upon Pst infection in vivo, overexpression of TaBZR2 increased total chitinase activity, whereas RNAi-mediated silencing of TaBZR2 reduced total chitinase activity. Taken together, our results suggest that TaBZR2 confers broad-spectrum resistance to the stripe rust fungus by increasing total chitinase activity in wheat.

Trehalose-6-phosphate phosphatase (TPP) genes take part in trehalose metabolism and also in stress tolerance, which has been well documented in many species but poorly understood in wheat. The present research has identified a family of 31 TPP genes in Triticum aestivum L. through homology searches and classified them into five clades by phylogenetic tree analysis, providing evidence of an evolutionary status with Hordeum vulgare, Brachypodium distachyon and Oryza sativa. The exon-intron distribution revealed a discrete evolutionary history and projected possible gene duplication occurrences. Furthermore, different computational approaches were used to analyze the physical and chemical properties, conserved domains and motifs, subcellular and chromosomal localization, and three-dimensional (3-D) protein structures. Cis-regulatory elements (CREs) analysis predicted that TaTPP promoters consist of CREs related to plant growth and development, hormones, and stress. Transcriptional analysis revealed that the transcription levels of TaTPPs were variable in different developmental stages and organs. In addition, qRT-PCR analysis showed that different TaTPPs were induced under salt and drought stresses and during leaf senescence. Therefore, the findings of the present study give fundamental genomic information and possible biological functions of the TaTPP gene family in wheat and will provide the path for a better understanding of TaTPPs involvement in wheat developmental processes, stress tolerance, and leaf senescence.

Sustainability of winter wheat yield under dryland conditions depends on improvements in crop photosynthetic characteristics and crop yield. Therefore, studying the effects of different sowing methods and nitrogen rates on photosynthetic characteristics of flag leaves, nitrogen translocation, and yield could be an effective strategy to improve the crop yield. In this study, four nitrogen application concentrations and two sowing methods were used. The results showed that the photosynthetic rates were the highest at different stages of wide-space sowing (WSS) after flowering. Nitrogen concentration of 240 kg ha -1 improved the photosynthetic characteristics and significantly increased the net photosynthesis, stomatal conductance, and transpiration rate after flowering and significantly reduced the intercellular CO2 concentration compaired to other nitrogen concentrations. Our overall findings suggested that WSS nitrogen treatment with 240 kg ha -1 enhanced photosynthetic characteristics of flag leaves and nitrogen content of the plants leading to high yield under dryland conditions. Highlights• Nitrogen fertilizer can significantly improve the net photosynthetic rate of winter wheat • Different sowing methods can promote an increase of intercellular CO2 • WSS with nitrogen concentration of 240 kg ha -1 improves wheat yield in Loess Plateau area in the arid regions of North China (Li et al. 2002, Ma et al. 2005. The Loess Plateau in China covers about 0.65 million km 2 area and has the population of 108 millions (Wang et al. 2016). The Loess Plateau has a semiarid climate with low and variable rainfall from 300-700 mm (Li et al. 2010). Nitrogen (N) deposition has dramatically altered terrestrial ecosystem properties and processes, such as plant nutrient cycling, photosynthetic carbon