异丙甲草胺对水稻生物性状及产量的影响

【目的】研究异丙甲草胺对水稻各生物性状及产量的影响,找出造成水稻减产的关键因子,为针对性选育高耐受水稻品种及异丙甲草胺水田安全应用提供依据。【方法】采取室内琼脂培养与室外田间试验相结合的方法,测定不同异丙甲草胺浓度下水稻T优227的发芽率、苗高、种根长、鲜重、分蘖数、谷粒数、结实率、千粒重等生物经济性状。【结果】异丙甲草胺对水稻种子发芽率、谷粒数和结实率有明显影响,对苗高、种根长、鲜重、分蘖数及产量等有一定影响。其中,发芽率随着药液浓度的上升呈逐步下降趋势,以2.0000 g/L处理的发芽率最低,仅为清水对照的45.6%;低浓度的异丙甲草胺（0.025 mg/L）抑制水稻幼苗生长,但对种根长、鲜重有促进作用,与对照相比苗高降低了5.7%,种根长增长了4.1%、鲜重增加了9.5%;随着药液浓度的提高,促进作用转为抑制作用,药液浓度为2.000 mg/L时,苗高、种根长和鲜重分别为对照组的9.6%、28.1%和30.9%。异丙甲草胺315 g/ha处理的谷粒数、结实率和产量均最低,产量为7723 kg/ha,减产17.8%。【结论】异丙甲草胺对水稻各个生长期均有一定影响,结实率与分蘖谷粒数受影响是导致水稻减产的主要原因。

Effects of metolachlor on biological characters and yield of rice

【Objective】The effects of metolachlor on biological characters and yield of rice were studied to find out the main factors for yield reduction and provide references for screening high-tolerant rice varieties and safety application of metolachlor in the paddy field. 【Method】Laboratory experiment combined with field experiment were used to measure the indexes including the germination rate, shoot height, taproot length, fresh weight, tiller number, grain number, seed setting rate and 1000-grain weight of T227 among the different treatments. 【Result】The results showed metolachlor had obvious effects on germination rate, grain number and seed setting rate and moderate effects on seedling height, taproot length, fresh weight, tiller number and yield. The germination rate reduced with the increasing of chemical concentration. The germinated rate was 45.6% of the control when metolachlor was applied at the concentration of 2.0000 g/L. Low concentration like 0.025 mg/L metolachlor suppressed seedling growth but promoted the growth of root length and fresh weight. Compared with the control, the seedling height, taproot length and fresh weight was down by 5.7%, up by 4.1% and up by 9.5%. However,the rate was 9.6%, 28.1% and 30.9% when concentration of metolachlor increased to 2.000 mg/L in agar medium. In field experiment, the grain number, seed setting rate and yield was the lowest when the dosage of metolachlor was 315 g per ha. The yield was 7723 kg/ha, down by 17.8%over the control. 【Conclusion】The whole period of rice growth was affected by metolachlor, however, seed setting rate and grain number of tillers are the main factors leading to yield reduction.