Bacterial blight (BB) is caused by Xanthomonas oryzae pv. oryzae and is one of the most important diseases in rice. It results in significantly reduced productivity throughout all rice-growing regions of the world. Four BB resistance genes have been reported; however, introgression of a single gene into rice has not been able to sufficiently protect rice against BB infection. Pyramiding of effective BB resistance genes (i.e., Xa genes) into background varieties is a potential approach to controlling BB infection. In this study, combinations of four BB resistance genes, Xa4, xa5, xa13, and Xa21, were pyramided into populations. The populations were derived from crossing Ciherang (a widespread Indonesian rice variety) with IRBB60 (resistance to BB). Promising recombinants from the F6 generation were identified by scoring the phenotype against three virulent bacterial strains, C5, P6, and V, which cause widespread BB infection in most rice-growing countries. Pyramiding of genes for BB resistance in 265 recombinant introgressed lines (RILs) were confirmed through marker-assisted selection (MAS) of the F5 and F6 generations using gene-specific primers. Of these 265 RILs, 11, 34 and 45 lines had four, three, or two BB resistance genes, respectively. The RILs had pyramiding of two or three resistance genes, with the Xa4 resistance gene showing broad spectrum resistance against Xoo races with higher agronomic performance compared to their donor and recipients parents. The developed BB-resistant RILs have high yield potential to be further developed for cultivation or as sources of BB resistance donor material for varietal improvement in other rice lines.

Drought is envisaged as the greatest demolishing natural impacts throughout the world since it has observed extensive place of agronomical land sterile almost the world. It's the significant crop output-limiting producer, and elaborated learning of its result on plant enhancement dictation is diametrical. At present, drought tolerant hybrid maize has been trying to induce Bangladesh especially drought affected zone to identify the drought endurance maize genotypes. Consequently, a feasible pot study of 49 hybrid maize genotypes were directed to determine an adequate drought level to promote aliment and promotion of maize plant below the water stress conditions with treatment (control and drought) and three replications. The data were received after 35 days of sowing using appropriate procedures. Specially, the stomata were collected by the white transparent nail polish from the lower part of leaves. Descriptive statistic of the all traits like percentage of SPAD, leaf rolling (LR), maximum root length (MRL), maximum shoot length (MSL), root dry matter (RDM), shoot dry matter (SDM), length of stomata (LS), width of stomata (WS), thickness of stomata (TS), total dry matter (TDM) and ANOVA for control and drought condition individually showed significant (P < 0.05) variations among the germplasm for their genotypes, treatment and interaction. The first fourth principal components (PCs) narrated about 82.0% of the total variation. Cluster analysis placed the 49 hybrid into 6 main groups among those cluster; groups five showed the maximum number mean value of traits. The highest positive relationship was obtained from TS, WS, RDM, SDM and TDM traits by forming genotype-traits bi-plot of 11traits of 49 genotypes. After analyzing, it is explicit that G18 (CML-80 × IPB911-16) and G22 (CZI-04 × IPB911-16) were the most tolerant hybrids maize genotypes and very susceptible hybrids maize genotypes were G16

The root system is the important organ of a plant, helping to anchor the plant and take up nutrients from the soil. The purpose of this investigation was to determine the magnitude of the root network system (RNS) through phenotypic variability in a broad range of maize inbred lines. The GiA Root software was used to identify root attributes from images. After germination, the inbred lines were grown hydroponically for 15 days in a high-lux plant growth room with low phosphorus (LP) and normal phosphorus (NP) treatments. Variance analysis revealed a large range of variability present among the inbred lines, with intermediate to high heritabilities ranging from 0.59 to 0.95 for all RNS traits, demonstrating uniformity through the experiments. The proportions of genetic variance ranged from 0.01–0.60 in different maize RNS traits. A strong positive linear relationship between best linear unbiased predictors (BLUPs) with estimated means was found for all the RNS traits. The Euclidean genetic distances between the studied inbred lines ranged from 0.61 to 29.33, showing a higher amount of diversity. More than 79% of the overall genetic variation was explained by the first three principal components, with high loadings from the measurements of network length (NWL), network surface area (NWSA), network perimeter (NWP), network area (NWA), the maximum number of roots (MANR), median number of roots (MENR), network volume (NWV), network convex area (NWCA), specific root length (SRL), network depth (NWD), number of connected components (NCC), and network width (NWW). The biplot of genotype by trait interaction exposed superior genotypes with a relatively high expression of favorable trait combinations. Some outstanding genotypes with higher values of most RNS traits were identified through MGIDI analysis. These lines may be convenient for enhancing LP tolerance in maize.