| Yield is one of the most important goal traits in the hybrid rice breeding andproduction. Yield breeding is faced with pressure and bottleneck of continuousbreakthrough, as well as has taken great achievements. Molecular marker techniquesused in breeding research is a main route in current and coming period, which providesan effective method for rice heterosis breeding. In this paper, we selected functionalgenetic markers related to rice yield to evaluate the role of functional gene markers ingenetic diversity, exploring the genetic relationship, genetic differences and geneticdifferentiation of rice parents based on functional genes, and revealed chinese three-linehybrid rice backbone parents’ pro-domesticated differences and genetic diversity in thefunctional locus in order to provide a reference for genetic diversity improving and newgermplasm creating guidance.At the same time, making use of yield and yieldcomponents factor related to functional markers, analysis the correction betweenmolecular markers genetic distance and heterosis, to explore the possibility of heterosisprediction, hope to provide new ways for heterosis breeding. The conclusions as listedbelow:①Genetic diversity of three-line hybrid backbone rice parents based on functionalgenetic markers related to yieldFunctional gene SSR markers related to rice yield from44literatures were used todetect genetic diversity among76chinese three-line hybrid rice parents, of which37primers showed polymorphism and86total alleles loci were detected; the percentage ofpolymorphic loci (p) is84.09%. While the number of effective alleles(ne) were62.95,of which73.2%, nei’s genetic diversity index(he) ranged from0.049to0.831, averagefor0.650. The genetic similarity (GS) of76varieties ranged from0.323to0.973,average for0.650. UPGMA cluster analysis showed that76accessions can be classifiedinto two distinct classes of maintainer lines and restoring lines, at similarities coefficientof0.618. The coefficient of genetic differentiation(gst) was0.151, belonging to highvariation level, and the nei’s genetic distance (GD) was0.51. The studies suggested thatthe functional gene markers had a high dna polymorphisms detection efficiency, and canbe used as a useful tool for their accuracy and reliability of measuring genetic diversity.The backbone parents in research showed nearer genetic relationship, higher homologysort of genetic basis. However, there still showed higher genetic differentiation between maintainer line and restoring line, suggesting that there was a higher space of usingheterosis breeding in the yield of rice parents.②The correlation between genetic distance based on rice yield functional genemarkers and heterosis4maintainer lines and10restoring lines as well as5maintainer lines and5restoring lines on the basis of4×10NCII and5×5NCII design were set up in twoyears, with the use of49SSR markers related to number of effective panicles per plant,filled grain number per panicle and1000-grain weight, analyzing the correlationbetween genetic distance and heterosis. The results showed that the testing effect offunctional markers was satisfactory. Yield form factors marking genetic distance forparent clustering were divided correctly.Genetic distance based on yield related to markers showed no significantcorrelation with control heterosis and mean heterosis, and none with compositionfactors. The results was difficult for heterosis prediction.The significance level of marked genetic distance based on three yield compositionfactors and corresponding heterosis was not completely consistent in two year’smaterials. However, genetic distance based on1000-grain weight related to markers canbe used for heterosis prediction (r=0.536**, r=0.283**), while genetic distancebased on number of effective panicles per plant and filled grain number per paniclerelated to markers showed a significant correlation with corresponding charactersheterosis in every levels, which was difficult to be used for heterosis prediction. |
PDF Full Text Request