光强与施氮量对水稻南粳45光合特性和产量构成的影响

以武育粳3号,新品系108为对照,在大田栽培条件下,研究南粳45在225.0、300.0、345.0kg.hm-2施氮量下,其分蘖期、拔节期和开花后的生长和光合生理指标,鉴定其耐光氧化和耐阴特性,并在成熟期考察产量构成因子。结果表明,与武育粳3号、新品系108相比,在施氮300.0 kg.hm-2下,南粳45单株产量分别提高了24.89%、5.40%;在不同生育期以及不同的施氮量下,南粳45具有较高的光合能力,尤其在拔节期;人工光氧化处理后,其最大的光化学效率(Fv/Fm)衰减较少;遮阴条件下,干物质下降较缓,结实率较高,属耐光氧化和耐阴品种。可见,南粳45在不同生育期均具有高光合能力和适应广幅变动的光强特性,这可能是南粳45获得高产的重要生理基础。

Effect of Light Intensity and Nitrogen Level on Photosynthetic Characteristics and Yield of Japonica Rice Cultivar Nanjing 45

With Wuyujing 3 and 108 line as control,Japonica rice variety Nanjing 45 with super-high-yielding,early harvesting and late maturity was transplanted in the field with low nitrogen level(LN,150.0 kg·hm-2),medium level(MN,300.0 kg·hm-2),high level(HN,375.0 kg·hm-2) and measured growth and photosynthetic performance at tillering stage,jointing stage and post-flowering,as well as yield components at heading stage,to evaluate the tolerance to photooxidation and shading characteristics.The results showed that,as compared with Wuyujing 3 and 108 line,individual plant yield of Nanjing 45 increased 24.89% and 5.4% in MN treatment respectively.Also in different growth periods and different nitrogen application,Nanjing 45 got a better photosynthetic capacity.Particularly,Pn of Nanjing 45 increased by 8.33%,8.56% and 2.33%,respectively;After photooxidation treatment,Fv/ Fm in Nanjing 45 decreased less.Under shading treatment,seed setting rates and dry matter accumulation decreased less.The photosynthetic traits and applicability mentioned above may be an important physiological basis for high yield in Nanjing 45.It should be noted that formation of rice yield was significantly related to their photosynthetic capacity during 30 d after flowering.So it could also be a reliable physiological yield potential of rice.