Development of New Restorer Lines Carrying Some Restoring Fertility Genes with Flowering, Yield and Grains Quality Characteristics in Rice (Oryza sativa L.).

Mamdouh Awad-Allah,Mohamed El-Diasty,Manal Said,Mohamed Mahmoud,Mohamed Abdelkader,Mohamed Abdein,Nehal Elekhtyar,Sahar Shamseldin,Azza Mohamed,Mohamed El-Abd

doi:10.3390/genes13030458

Abstract

This study was carried out using 22 promising restorer lines of rice and their parental lines to study genetic variability and genetic advance for yield and yield-associated grain quality traits and floral traits. These genotypes are evaluated in a replicated trial using Randomized Complete Block Design (RCBD) with three replications at the Experimental Farm of Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt, during the seasons from 2012 to 2020. Analysis of variance revealed that highly significant variations were observed among the genotypes for all the studied characters. Both GCV% and PCV% were high for the number of spikelets per panicle, the number of filled grains per panicle, and panicle weight. The genetic advance in the percentage of mean was high for days to plant height, panicle length, number of spikelets per panicle, number of filled grains per panicle, panicle weight, grain yield per plant, anther length, anther breadth, duration of floret opening, and head rice percentage. Mean performance of the rice genotypes indicated that the genotypes NRL 59, NRL 55, NRL 62, NRL 63, NRL 66, and NRL 54-2 were promising for grain yield and associated desirable traits. Thus, some of these promising lines can be promoted as a new rice variety and could be used as a source for developing new hybrid combinations in hybrid rice breeding programs. The percentage of advantage over better parent and Giza 178 as the commercial variety was significant and there were highly significant desirable values among the genotypes for all the studied traits in the two years, indicating that the selection is effective in the genetic improvements for these traits.

Highlights

IntroductionRice is one of the most important crops for almost all of the world especially developing countries [1,2]
Rice is a staple food and feed crop
A total of 22 lines (Table 1) of their performance according to their phenotypic, grain yield, yield acceptability, and grain quality were selected for evaluation in randomized complete block design with the Giza 178 rice variety as a check in three replications during the 2019 and 2020 rice seasons

Summary

Introduction

Rice is one of the most important crops for almost all of the world especially developing countries [1,2]. The cytoplasmic male sterility (CMS) is associated with a mitochondrial mutation that causes an inability to produce fertile pollen. The fertility of CMS plants is restored in the presence of a nuclearencoded fertility restorer (Rf ) gene This is found in lead rice-type CMS, discovered in the indica variety ‘Lead Rice;’ the fertility of the CMS plant is restored by the single nuclearencoded gene Rf2 in a gametophytic manner. As Rf2 does not encode a pentatricopeptide repeat protein, unlike a majority of previously identified Rf genes, the data from this study provide new insights into the mechanism for restoring fertility in CMS [5]. CMS is a maternally inherited trait, and is often associated with the unusual ORFs found in mitochondrial genomes [6]

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Discussion

Conclusion