Characterization of a panel of contrasting rice genotypes for low phosphorus tolerance using morphological and molecular markers
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Date
2018
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College of Post Graduate Studies in Agricultural Sciences, Central Agricultural University, Imphal
Abstract
Rice (Oryza sativa) belongs to the family Poaceae has chromosome number of 2n=24. Rice is considered as a major food crop across major countries worldwide. There are many problems which affect rice productivity. Soil acidity, anabiotic factor, is one of the factors causing low yield in rice. 49 million ha of the total land area in India is affected by soil acidity. Major portion of acidity affected soil are concentrated in north-eastern part of India due to extreme levels of soil acidity. Phosphorus deficiency is a huge problem faced in NEHRs of India due to acidic soil. Phosphorus forms precipitation reactions with aluminium (Al) and iron (Fe) in acidic soils and the complex of P in Al-P and Fe-P minerals under acidic conditions tends to be stable. In this stable form, P is not available for uptake by plants and its availability is therefore, reduced. Therefore this affects rice functions like energy transfer, photosynthesis, transformation of sugars and starches, nutrient movement within the plants. The present study aimed at evaluating 60 diverse rice genotypes performance with respect to 15 different traits under lowland, acidic P deficient soil conditions using morpho-physiological parameters and to study the association between candidate gene based markers and phosphorus deficiency tolerance. A panel of 60 selected genotypes was selected based from the previous study on 110 genotypes and grown in the field. Data were collected on 58 plants only as the other 2 plants could not survive. On the basis of the 15 traits above, 20 top performing and 20 bad performing lines were selected for further evaluation. Genotypes like BAM 4115, LR 23, LR 21, BAM 8381, LR 19, LR 18-2 and LR 5 had the highest tiller no. at 30 days and BAM8315, BAM 6921, LR 5 and BAM 8381 showed the highest tiller no. at 60 days, LR 1 showed the highest grain yield. The genotypes LR 1 and BAM 4054 showed the largest PUE content. With respect to phosphorus uptake the genotypes BAM 742, BAM 2815, BAM 1098, BAM 8381, UR 29, BAM 811, BAM 56, BAM 712, BAM 1689, BAM 747, BAM 698, BAM 785, BAM 758 and BAM 759 were better performer.The correlation matrix showed that panicle length, leaf area and biological yield were significantly correlated grain yield. High correlation was also observed for tiller number at 60 days with traits like panicle number (0.736), biological yield (0.647), days to flowering (0.600) and grain yield (0.593) at 1% level of significant (0.325). P content was significantly correlated with TN30, TN60 and GY. PUE of flag lead was significantly correlated with DTF and BY. However, PUP of flag lead was negativelycorrelated with most of the traits including GY, TN and PUE. Significant correlation of our data with previous field data (2014) for 11 agronomic traits suggests that the genotypes and traits identified can be used for various breeding and crop improvement programmes for low P tolerance. Genotyping with candidate gene based makers showed polymorphism for markers like K46-2, PR 111-3 and HvSSR 06-06. Marker trait association revealed significant association of marker, PR111-3 with leaf area, grain yield and spikelet fertility. Marker K46-2 showed significant association with panicle length and test weigh.