硅氮互作改善优质稻植株生理生态特性

Silicon and Nitrogen Improving the Eco-physiological Characteristics of High Quality Rice

本研究以2个水稻品种‘桂农占’和‘黄华占’为供试材料,设置3个氮水平(120、180、240kg/hm^2分别表示为低氮、中氮和高氮),3个硅水平(0、225、450 kg/hm^2分别表示为低硅、中硅和高硅),交叉互作,研究硅氮互作对水稻植株形态、物质积累、光合作用及碳氮代谢的影响。结果表明:硅氮互作有助于增加水稻的穗数、株高及生物量。中氮或中硅浓度能显著提高水稻叶片的光合作用,以‘桂农占’效果更为明显,光合速率分别提高了19.21%和8.75%。在不同氮水平下,施用中等浓度硅可以提高‘桂农占’和‘黄华占’叶片的硝酸还原酶活性,分别比低硅处理增加46.82%和85.43%;在成熟期低氮水平下,2个水稻品种硝酸还原酶活性随硅浓度的增加而增加。对于叶片蔗糖转化酶活性,2个水稻品种均为抽穗期>分蘖期>成熟期,且各处理下,‘黄华占’蔗糖转化酶活性基本大于‘桂农占’。总体上来讲,低氮高硅,中氮中硅的硅氮配比组合,有助于促进水稻生长发育和物质代谢。

Two rice varieties’Guinongzhan’and’Huanghuazhan’were used as the material to study the effects of N and Si application on rice plant growth and physiological traits.Three levels of nitrogen 120,180 and 240 kg/hm^2,indicated by N1,N2 and N3,respectively,and three levels of silicon application 0,225 and 450 kg/hm^2,indicated by Si1,Si2 and Si3,respectively,were selected.The interaction of silicon and nitrogen could increase the panicle number,plant height and biomass of rice.The N2 and Si2 treatment significantly improved the photosynthesis of leaves,especially for’Guinongzhan’.The photosynthetic rate increased by 19.21% and 8.75%,respectively.Under different N application levels,medium Si level(Si2)significantly increased the nitrate reductase(NR)activity of leaves.Compared with Si treatment,Si2 treatment increased NR by 46.82% and 85.43% for’Guinongzhan’and’Huanghuazhan’,respectively.NR activity increased with the increase of Si level at maturity stage under low N level.For sucrose invertase(SI)activity,both varieties showed the trend of different growth stage:heading stage>tillering stage>mature stage,and SI activity in’Huanghuazhan’was higher than that in’Guinongzhan’.The results suggested that low N and high Si,medium N and medium Si treatment could significantly promote rice growth and metabolism.