籼粳衍生系杂交稻光合特性与水分利用效率遗传解析OA

[Objective]Genetics related to the photosynthesis and water use efficiency(WUE)of indica-japonica hybrids was studied.[Methods]Sixty indica-japonica hybrids were obtained by crossing 5 indica-type cytoplasmic male-sterile(CMS)lines with 12 indica-japonica derived restorer lines using the North Carolina Ⅱ(NCⅡ)mating design.Photosynthetic parameters and WUE were measured on flag leaves at full heading stage of the plants.[Results]Substantial genetic variations existed on all target traits of the hybrids.The non-additive effects accounted predominately for 63.30%-75.92%of the total genetic variance.The remaining 24.08%-36.70%additive effects were primarily derived from the restorer lines and insignificantly from the sterile lines.The broad-sense heritability was high at 83.46%-98.08%,while the narrow-sense heritability was low at 20.79%-36.03%.The path coefficient analysis showed Tr to exert the strongest positive direct effect on Pn of 0.532,and WUE a weak negative direct effect of-0.131.Pn significantly and positively correlated to the seed-setting rate with a Pearson correlation coefficient(r)of 0.352,to the filled grains per panicle with an r of 0.277,and to the grain yield per plant with an r of 0.341.[Conclusion]Targeting the physiological indicators of a high Ci,a low-to-moderate Gs,and strong Tr direct effect on Pn,a high-yield rice variety efficient in photosynthesis and water utilization could possibly be bred by crossing Minghui 398 or Minghui 417 with Minghui 502.