Physiological characterization of quantitative trait loci involving for biomass production in rice

2015 Fiscal Year Final Research Report

• Project/Area Number: 25870780
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Crop production science; Science in genetics and breeding
• Research Institution: Toyo University
• Principal Investigator: Hirotsu Naoki 東洋大学, 生命科学部, 准教授 (40584389)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 量的形質遺伝子座 / 成長解析 / 窒素吸収 / ショ糖リン酸合成酵素 / 初期生育 / 乾物生産

Outline of Final Research Achievements

I investigated the growth mechanism of rice by quantitative trait locus (QTL) analysis. Four QTLs associated with increased in plant growth rate were identified which were derived from ‘Kasalath’ alleles on chromosomes 1, 6, 8 and 12. This was achieved by evaluating the net dry weight gain between two developmental points. Physiological analysis revealed that the QTL on chromosome 1 (qEGR1) increased the relative growth rate (RGR) by enhancing the net assimilation rate (NAR). High RGR and NAR were facilitated by an increase in gene expression of OsSPS1 that encodes the rate-limiting enzyme in sucrose synthesis. In contrast, QTLs on chromosomes 6, 8 and 12 (qEGR6, qEGR8 and qEGR12) were associated with an increase in uptake of NH4+, the major nitrogen source for rice. These results suggest that growth mechanism is controlled by multiple traits but sucrose biosynthesis and NH4+ uptake play the key role in determining early growth rate of rice plant.

Free Research Field

作物生理学