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IDENTIFICATION OF RESTORERS AND EFFECT OF WA CYTOPLASM ON THE PHYSICO-CHEMICAL GRAIN QUALITY CHARACTERISTICS IN HYBRID RICE (O. sativa L.)
| Content Provider | KrishiKosh-Indian National Agricultural Research System |
|---|---|
| Advisor | Jaiswal, H. K. |
| Researcher | Waza, Showkat Ahmad |
| Abstract | The most important challenge in rice hybrid breeding is to ensure that the heterotic rice hybrids possess grain quality that is at least comparable, if not superior, to that of inbred popular varieties grown by farmers. The grain quality of rice hybrids depends on the grain quality of parents. It is therefore important that only parents that show consumer acceptability are chosen to make hybrids. Thus, identification of restorers among elite quality cultivars can serve as an important tool for the development of better quality rice hybrids. In case of hybrid rice, quality concerns assume enhanced importance mainly due to two reasons; first the marketable produce is a bulk of segregating endosperms of F2 generation, and second, the apprehension regarding an effect of sterility inducing cytoplasm on physico-chemical grain quality traits. Keeping in view the above mentioned facts, the present investigation entitled “Identification of Restorers and Effect of WA Cytoplasm on the Physico-chemical Grain Quality Characteristics in Hybrid Rice (O. sativa L.)†was carried out. Twenty one genotypes of rice (Oryza sativa L.) were used for identification of restorers and maintainers for three cytoplasmic male sterile (CMS) lines, viz., IR-58025A, IR-68897A and Pusa 6A. The pollen parents showing stable fertility restorer behaviour (over years) were evaluated with the help of molecular markers to establish the presence of fertility restoring genes. The crosses between CMS lines and identified restorers were used to study heterosis and combining ability for various yield and quality traits. The differences between CMS line x restorer and maintainer line x restorer cross combinations were evaluated to study the cytoplasmic effect on various traits of commercial importance. Six genotypes (Sanwal Basmati, Pusa Sugandh-2, Pusa Sugandh-3, Pusa Sugandh-5, Pusa 2517-2-51-1 and HUR-JM-59221) were found to exhibit stable restorer behaviour for all the three CMS lines (IR-58025A, IR-68897A and Pusa 6A). Pusa-44 was found to exhibit the stable fertility restoring ability for IR-58025A, whereas Pusa Basmati-1121 revealed the stable restoring potential for IR-68897A. Three pollen parents (Pusa Basmati-1, Pusa-1460 and HUR-LP-191123) exhibited stable maintainer behaviour for all the three CMS lines. In addition, three genotypes viz., HURPB-1M-98, HURPB-1S-97 and TBD-2-1 were found to show the stable maintainer behaviour for CMS line IR-68897A. Rest of the genotypes were either stable partial restorers or stable partial maintainers for various CMS lines or their fertility restoration behaviour varied over years. The SSR markers, which have been previously reported to be linked to fertility restorer (Rf) gene(s) were deployed to establish the presence of fertility restoring genes for WA CMS lines of rice. The SSR markers RM171 and RM6100 linked to Rf4 gene on chromosome 10, and SSR markers RM315 and RM443 linked to Rf3 gene on chromosome 1 were used for evaluation. The primers RM171 and RM6100 revealed distinguishing banding pattern between CMS lines and fertility restorers, but no such polymorphism was observed for the primers RM315 and RM443. The genotypes HUR-JM-59221 and Pusa-44 revealed slightly different banding pattern than rest of the pollen parents. The mean performance of 20 rice hybrids obtained from three CMS lines and eight pollen parents showing stable fertility restoring ability, along with their parental lines and checks were studied for both yield and quality traits. Heterosis was estimated as per cent increase or decrease in estimates of various traits over respective better parents and standard varieties (checks). For yield traits, the heterosis was estimated for days to 50 percent flowering, days to maturity, plant height, number of effective tillers per plant, 100 grain weight and grain yield per plant. In case of quality traits, the heterosis was estimated for hulling recovery, milling recovery, head rice recovery, kernel length before cooking, kernel breadth before cooking, kernel length after cooking and kernel breadth after cooking. For the quality parameters viz., kernel length/breadth ratio before cooking, kernel length/breadth ratio after cooking, kernel elongation ratio, elongation index, alkali spread value, amylose content and aroma usual calculations of heterosis were not applied. The performance of F1s for these parameters was evaluated by simple comparison between their mean value and that of standard checks. The findings of present study suggest that relative magnitude of superiority differed from character to character and cross to cross. Majority of the hybrids recorded high heterosis for grain yield. Among the various hybrids exhibiting desirable value of heterosis, IR-68897A x Pusa Sugandh-3, IR-58025A x HUR-JM-59221 and IR-58025A x Pusa Sugandh-5 were top performers for grain yield per plant. The hybrid, IR-68897A x Pusa Sugandh-3 recorded highest yield per plant, and was among the best three performers for traits, days to 50% flowering, days to maturity and number of effective tillers per plant. For quality traits, the relative performance of different cross combinations with respect to standard checks was in both favourable and unfavourable directions. Among the three best performing hybrids for grain yield, cross combination IR-58025A x Pusa Sugandh-5 revealed better performance for majority of the quality traits. Thus, IR-58025A x Pusa Sugandh-5 may be considered as the best cross combination for both yield and quality traits. For hybrid IR-68897A x Pusa Sugandh-3, the female parent did not show significant desirable GCA effect for grain yield as well as most of the quality attributes. However, the male parent in this hybrid recorded significant desirable GCA effect for grain yield and most of the yield as well as quality traits. For IR-58025A x Pusa Sugandh-5, the female parent recorded significant desirable GCA effect for grain yield as well as most of the quality traits. The male parent was observed to show negative value of GCA effect for grain yield, but revealed significant desirable GCA effect for most of the quality traits. The WA cytoplasmic influence evaluated in the present study for different traits was found to be highly cross-specific, depending on the nuclear background of CMS line and fertility restorer. Majority of the traits were not significantly affected by the sterile cytoplasm in most of the cross combinations. Most significant effect of the sterility inducing cytoplasm was reduction in length of cooked kernel and decrease in amylose content. The cytoplasm had significant positive influence on days to 50% flowering, days to maturity and elongation index, in some of the cross combinations. However, the traits, 100 grain weight, yield per plant, hulling recovery, milling recovery, kernel length before cooking, kernel breadth before cooking, kernel breadth after cooking and alkali spread value were found to be negatively influenced by the sterility inducing cytoplasm. For kernel length/breadth ratio before and after cooking, there were favourable as well as unfavourable cytoplasmic effects depending upon the parental combination. The traits, plant height, effective tiller per plant, head rice recovery and elongation ratio were not significantly influenced by male sterile cytoplasm. Male sterility inducing cytoplasm had no effect on aroma. |
| File Size | 6956678 |
| File Format | |
| Language | English |
| Publisher | Institute of Agricultural Sciences |
| Publisher Place | Varanasi |
| Access Restriction | Open |
| Subject Keyword | Hybrid Rice Combining Ability Heterosis Identification of Restorers Effect of Wa Cytoplasm Physico-chemical Grain Quality |
| Content Type | Text |
| Resource Type | Thesis |
