Evaluation Of Rice Genotypes Research Articles

Evaluation of rice genotypes against rice leaf folder, Cnaphalocrosis medinelis Guenee in Koshi region of Bihar

Evaluation of rice genotypes against rice leaf folder, Cnaphalocrosis medinelis Guenee in Koshi region of Bihar

Evaluation of rice genotypes on seed attributes and agronomic performance for developing direct-seeded cultivar

<abstract> <p>Direct seeding of rice (DSR) may give benefit in using water and labor more efficient and reduce production costs. This study purposes to investigate the character of the seeds, their early vigor traits, the growth and development of rice plants for developing DSR cultivar. The research was conducted in four stages: the measurement of the size of the seed, endosperm, and embryo; the germination test in the laboratory; seedling test using experimental pots; and testing the agronomic performance on transplanting and direct seeding methods in a plastic house. Seed material used eight breeding lines of IPB University and two released varieties. The results of study showed that each genotype had different characteristics of seed, endosperm, and embryo in both weight and area. Seed weight becomes the most dominant in the emergence of superior EV traits, whereas the more seed weight indicates faster radicle emergence and more weight of seedling. DSR method compared to transplanting showed performance such as taller plant, higher leaf area and photosynthesis rate at early growth stage, earlier heading time, and higher plant dry weight since early growth until 65 days old. The seed characters have positively correlation to dry weight of seedlings, number of leaves, leaf area, and canopy dry weight. We also found that higher area of endosperm and embryo significantly correlated to have faster plumule emergence, higher leaf area and plant height. Candidate genotypes for DSR would be further investigated in the field trial agronomically.</p> </abstract>

Evaluation of rice genotypes against varying population densities of root-knot nematode Meloidogyne graminicola identifies potential sources for resistance breeding

Evaluation of rice genotypes against varying population densities of root-knot nematode Meloidogyne graminicola identifies potential sources for resistance breeding

Evaluation of Rice Genotypes from Crossing based on Salinity Stress Tolerance Indices

Evaluation of Rice Genotypes from Crossing based on Salinity Stress Tolerance Indices

Morpho-genetic Evaluation of Rice Genotypes (Oryza sativa L.) Including Some Varieties and Advanced Lines Based on Yield and Its Attributes

In breeding programs, direct selection based on yield is very difficult due its polygenic nature. Therefore breeders need to consider association of numerous yield related attributes with yield and among themselves. In this study, 43 rice genotypes including some released varieties and advanced lines were evaluated based on morpho-genetic parameters. A field experiment was conducted at the field laboratory of Genetics and Plant Breeding Department, Bangladesh Agricultural University using a randomized complete block design with three replications. Analysis of variance revealed that all genotypes exhibited significant variations (P ≤ 0.001) for all considered traits except leaf length indicating a wider extent of variability for selection. Greater phenotypic coefficient of variation (PCV) compared to corresponding genotypic coefficient of variation (GCV) for all the traits representing environmental influence on the studied traits. High GCV and PCV values were observed for the most important yield related traits like seedling height, leaf length, flag leaf area, flag leaf angle, number of effective tiller hill-1, 1000-grain weight and yield plant-1. These results suggested that selecting genotypes with these traits could be way for attaining enhancement in rice yield. Majority of the traits displayed high heritability (>60%) with high genetic advance (>20%) pointing towards non-additive gene action suggesting selection should be practiced carefully. Correlation study explored significant positive and negative association among yield and related attributes. Principal component analysis revealed the most important traits contributing to the variations among the genotypes. According to cluster analysis, 43 genotypes were grouped into 4 clusters among which genotypes within cluster I and cluster III might be selected for future rice breeding programs regarding yield potentiality and other related traits.

LEA Gene Expression Assessment in Advanced Mutant Rice Genotypes under Drought Stress.

Late embryogenesis abundant (LEA) proteins are primarily found in plants stem, roots, and other organs and play significant roles in tolerance to several abiotic stresses. Plants synthesize a discrete set of LEA proteins in response to drought stress. In this study, the expression patterns of LEA genes were investigated in two advanced mutant rice genotypes subjected to the drought stress condition and different physiological traits including photosynthetic rate, leaf chlorophyll content, and photosystem II (PSII) photochemical efficiency (Fv/Fm) which were analyzed to confirm their drought tolerance. Five LEA genes (OsLEA1, OsLEA2, OsLEA3, OsLEA4, and OsLEA5) were used in the evaluation of rice genotypes and were significantly upregulated by more than 4-fold for MR219-4 and MR219-9. The upregulated genes by these two varieties showed high similarity with the drought-tolerant check variety, Aeron1. This indicates that these advanced mutant genotypes have better tolerance to drought stress. The changes in the expression level of LEA genes among the selected rice genotypes under drought stress were further confirmed. Hence, LEA genes could be served as a potential tool for drought tolerance determination in rice. MR219-4 and MR219-9 were found to be promising in breeding for drought tolerance as they offer better physiological adaptation to drought stress.

English

English

Evaluation of rice genotypes for fertility restoration against WA andO. perenniscytoplasm based cytoplasmic male sterility

Five cytoplasmic male sterile (CMS) lines with Wild Abortive (WA) CMS source and one CMS line having Oryza perennis cytoplasm were crossed with 20 rice genotypes to assess their restorer/maintainer behaviour. All the 20 F1s with IR 66707A line having O. perennis cytoplasm produced only sterile hybrids. Most of the genotypes expressed differential fertility reactions when crossed with CMS lines having WA cytoplasm. The genotypes, IR 10198-66-2R, IR 65515-47-21-19, TNAU 94241 and TNAU 841434 were identified as effective restorers while ADT 43, ASD 19, CB 97083 and CO (R) 47 produced completely sterile hybrids with CMS lines carrying WA cytoplasm. Ten best heterotic combinations were identified based on economic traits.

Evaluation of Rice Genotypes under Propionate Stress

The objective of the present work was to evaluate the response of 25 rice genotypes to propionate, a compound largely produced in low‐drainage and high‐organic matter‐content soils. The work was performed in hydroponics with four doses and a random block design with three replications. The variables measured were root (RL) and shoot (SL) length, number of roots (NR), and root (RDM) and shoot (SDM) dry matter. Analyses of variance, relative performance, and regression fitting were performed, showing significance for most variables. The variable RL was the most affected by propionate, and the use of this variable for screening genotypes indicated 6 tolerant and 19 sensitive genotypes. Most tolerant genotypes belonged to irrigated japonica.

Evaluation of Rice Genotypes at Seedling Stage for Salinity Tolerance

Evaluation of Rice Genotypes at Seedling Stage for Salinity Tolerance