Dynamic Quantitative Trait Loci Analysis of Seed Reserve Utilization during Three Germination Stages in Rice

Abstract

In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed reserve utilization during the early (day 6), middle (day 10) and late (day 14) germination stages. The seedling dry weight (SDW) and weight of the mobilized seed reserve (WMSR) were increased, while the seed reserve utilization efficiency (SRUE) decreased, during the process of seed germination. The SDW and WMSR were affected by the seed weight, while the SRUE was not affected by the seed weight. A total of twenty unconditional and twenty-one conditional additive QTLs and eight epistatic QTLs were identified at three germination stages, and the more QTLs were expressed at the late germination stage. Among them, twelve additive and three epistatic QTLs for SDW, eight additive and three epistatic QTLs for WMSR and thirteen additive and two epistatic QTLs for SRUE were identified, respectively. The phenotypic variation explained by each additive QTL, epistatic QTL and QTL × development interaction ranged from 6.10 to 23.91%, 1.79 to 6.88% and 0.22 to 2.86%, respectively. Two major additive QTLs qWMSR7.1 and qSRUE4.3 were identified, and each QTL could explain more than 20% of the total phenotypic variance. By comparing the chromosomal positions of these additive QTLs with those previously identified, eleven QTLs might represent novel genes. The best four cross combinations of each trait for the development of RIL populations were selected. The selected RILs and the identified QTLs might be applicable to improve rice seed reserve utilization by the marker-assisted selection approach.

Effects of pre-harvest chemical application on rice desiccation and seed quality

“…Due to the emphasis placed on early planting and rapid and uniform emergence, the quality of seed production is an important issue in rice (Wang et al, 2010;Cheng et al, 2013). Seed development, maturity, and harvest management are critical considerations for maintaining high seed quality (Bewley et al, 2013).…”

Strategy for selection of soybean genotypes tolerant to drought during germination

“…The RSR, or remaining dry mass in cotyledons, is indicative of how much the initial reserve present in cotyledon was relocated during the stage of seed germination, i.e., the higher the RSR more energy is available to the process of germination. Features of use of seed reserves, like RSR, play important roles in seed vigor, implementing its germination and heterotrophic growth (Cheng et al, 2013).…”

Conditional quantitative trait locus mapping of wheat seed protein-fraction in relation to starch content

“…Once the contribution of a causal trait has been excluded, the remaining variation of the resultant trait is defined as conditional variation, or net variation, which indicates the extra effects of genes that are independent of the causal trait ). This method was first applied to the studies on QTL of developmental behavior in rice (Cheng et al 2013), maize (Osman et al 2013), cotton (Ye et al 2003), soybean (Jiang et al 2010;Han et al 2011), wheat Zhu et al 2011;Jiang et al 2013). Several studies on the analysis of multiple related traits in conditional QTL mapping methods (Zhao et al 2006;Wang et al 2012), defining the genetic relationship among different traits at the QTL level.…”