脱水剂对杂交水稻种子田间干燥效果的研究

摘要

为探索杂交水稻种子田间快速干燥技术，选用两种脱水剂（以A和B表示），分别以4个浓度在杂交水稻制种组合‘H638S ×R534’种子腊熟期喷施，以不喷施为对照，测定杂交种子田间含水量、种子粒重、发芽势、发芽率、活力及脯氨酸含量。结果表明：（1）A、B两种脱水剂均能使杂交水稻种子田间含水量快速降低。在喷施后连续5d晴天条件下，随着喷施浓度的增大，种子含水量下降的幅度加大；同一浓度处理，随着喷施天数的增加，种子含水量逐日下降，并呈现出前3 d急速下降，后2 d缓慢下降的趋势；平均日脱水速率在1.5～1.7个百分点，田间种子含水量降低7.0～8.5个百分点。（2）在供试浓度范围内，喷施脱水剂对适时收获的种子粒重无显著影响；随着药剂处理浓度的增大，种子的发芽势、发芽率和活力均呈现下降趋势；同一药剂处理浓度条件下，随着喷药后天数的增加，种子的发芽势、发芽率和活力也呈现下降趋势。（3）在满足种子田间含水量降低至18％的条件下，根据脱水剂对种子的发芽势、发芽率、活力及脯氨酸含量的影响，两种脱水剂以750～1500 mL／hm2浓度处理，适宜在喷药后4～5 d收获。（4）在第6、7天遇连续下雨并延迟到第8、9天收获的情况下，各处理的种子发芽势、发芽率及活力均较喷施后的第5天有较大幅度降低，故应注意及时收获。%In order to explore the rapid drying technology of hybrid rice seeds in the field,two dehydrating agents (A and B)with 4 concentrations (750、1500、2250、3000 mL/hm2 )were selected and sprayed in the mature stage of the hybrid rice combinations of‘H638S ×R534’. Hybrid seed moisture content,seed grain weight,germination potential,germination rate,vitality,and proline content were determined after harvest. The results showed that:(1 )dehydration agents A and B decreased the water content of hybrid rice seed in the field rapidly. If there are five consecutive fine weather days after spraying and as the agent concentration increased,the seed moisture content decreased more rapidly. At same concentra-tion,the seed moisture content declined rapidly in the first three days after spraying and followed slow decline in the next two days. The average dehydration rate was 1. 5%-1. 7%/d,the seed moisture content decreased by 7. 0-8. 5 percentage points within 5 d. (2)In the tested concentration range,dehydration agents did not affect seed weight significantly of the seeds harvested timely;As the concentration increased,seed germination potential,germination rate and vigor showed a de-cline trend;at the same concentration and with the increased spraying days,the seed germination potential,germination rate and vigor also declined. (3)On the condition of 18%seed moisture content in field,according to the effect of the dehydra-ting agent on seed germination potential,germination rate,vigor and proline content,the suitable concentration of the two dehydrating agents are with 750-1500 mL/hm2;the suitable harvest time is 4-5 days after spraying. (4)In the case of con-tinuous rain condition after spraying,if the harvest delayed to 8-9 days,the seed germination potential,germination rate and vigor were significantly lower than that harvested at 5 days after spraying. Harvest timely should take in mind.