UV-B辐射增强对水稻生长发育及其产量形成的影响

在盆载条件下，研究UV-B辐射（280-320nm）增强对3个不同类型水稻品种（组合）的生长发育及其产量构成的影响。结果表明，UV-B辐射增强明显抑制水稻生长，使株高变矮、分蘖数减少、叶面积和干物质量下降，但其抑制程度依品种、水稻所处的生长阶段的不同而不同；株高在苗期下降幅度最大，为9.4%-12.2%，干物质量在分蘖期下降幅度最大，地下部和地上部干物质量分别下降45.3%-59.8%、54.9%-59.0%，增强的UV-B辐射使水稻主茎不同叶位的出叶时间延迟，生育期延长，汕优63、南川、IR65600-85的抽穗时间分别比对照延迟2d、3d和7d，成熟期分别推迟3d、4d和9d，UV-B辐射增强明显降低水稻叶片的叶绿素和类胡萝卜素含量，叶片叶绿素a荧光诱导动力学参数Fv、Fv/Fm、Fv/Fo下降，与对照相比，汕优6.3、南川、IR65600-85叶片的净光合速率分别下降了11.9%、12.8%、29.7%，UV-B辐射增强使水稻每株有效穗、每穗总粒数、结实率、千粒重下降，最终导致水稻籽粒产量下降25.2%-31.1%。

Effects of enhanced ultraviolet-B radiation on growth development and yield formation in rice (Oryza sativa L.)

Effect of enhanced ultraviolet-B radiation (280-320 nm) on growth, development and yield formation in the three rice cultivars (Oryza sativa L.) under pot conditions were investigated. The results showed that enhanced ultraviolet-B radiation decreased rice height, tiller number, total leaf area and biomass, but the inhibitory rate varied in different cultivars and developmental stages. Plant height was decreased by 9.4%-12.2% in seedling stage, plant shoot and root of dry matter were decreased by 45.3%-59.8% and 54.9%-59.0% respectively in tillering period. The leaf emergence delayed, resulting in delayed time of flowering in Shanyou 63, Nanchuan and IR65600-85 by 2d, 3d and 7d, prolonged total growth period by 3d, 4d and 9d. Net photosynthesis rate of Shanyou 63, Nanchuan and IR65600-85 were decreased by 11.9%, 12.8% and 29.7%, respectively. Attributed to decreased contents of chlorophyll a, b, carotenoid and induction kinetics parameters of Fv, Fv/Fm and Fv/Fo. Effective panicle per plant, total grain number per panicle, filled grain rate and 1000-grain weight were decreased by enhanced UV-B radiation. Consequently the grain yields were reduced by 25.2%-31.1%.