不同养分管理对杂交稻生育后期功能叶生理活性和籽粒灌浆的影响

Effect of nutrient management on leaf physiology and grain filling at late growth stage in hybrid rice

研究了在施肥总量和NPK比例相同的条件下,不同时期施肥对水稻后期功能叶光合速率以及产量、粒重、结实率、籽粒灌浆速率的影响.结果表明,氮钾分次施肥对水稻产量有明显的影响,施用粒肥能显著地提高杂交水稻的产量,其中以粒肥中配以锌硼肥和BR的处理对产量的提高作用最为显著,比仅施基肥和分蘖肥的处理产量提高达30%.粒肥能延缓功能叶的衰老,使其在水稻生长后期仍维持较高的光合速率、灌浆速率和较长的灌浆时间,提高千粒重和结实率.加强后期的养分管理对杂交稻的影响比常规稻更显著.表明杂交水稻的粒重和结实率不仅受遗传控制,也受养分管理的影响.可以通过加强生育后期的养分管理提高杂交水稻的产量.加强水稻生长发育后期的养分管理还能显著改善稻米品质,如包括Asp、Lys、Ala、Gln等的氨基酸含量,在子实肥中加入锌能够显著地提高稻米中锌含量.

A field experiment was conducted to study the effect of nutrient management on rates of grain filling, photosynthesis and respiration of flag leaf during grain filling period, and grain yield of hybrid rice in comparison with the conventional rice cultivar. Applied with the same amount of NPK fertilizers, the timing and times of NK application greatly influenced grain yield of hybrid rice. That when NK was applied only as basal and tiller promoting fertilizer resulted in lowest single grain weight and total grain yield. At heading, the late stage of rice growth, top dressing with NK (10% of total of NK) together with a spray of (Zn+ B and BR) markedly increased grain yield especially in the hybrid rice. The yield increase of hybrid was attributed to improvement of plant growth and delay of plant senescence. Top dressing with NK at heading resulted in significant increase of photosynthetic rate and grain filling rate, prolonged duration of the grain filling period, and increase of single grain weight and grain setting. These results implied that grain development and ripening of hybrid rice grains are not totally genetically controlled, but regulated by nutrient management remarkably, especially NK and micronutrient such as B and Zn supply at the late growth stage. Nutrient management at late stage of rice growth also improved quality of rice grains such as increasing content of some amino acids including Asp, Lys, Ala, Gln. Moreover, rice Zn content was increased when Zn addition to the spray. 