第二复叶期喷施草甘膦对抗草甘膦大豆生理指标及产量构成的影响

IMPACT OF SPRAY GLYPHOSATE ON PHYSIOLOGICAL INDEX AND YIELD COMPOSITION OF GLYPHOSATE-RESISTANT SOYBEAN AT TWO-TRIFOLIOLATE LEAF STAGE

采用随机区组的设计方法,在第二复叶期喷施不同剂量的农达41%水剂,研究了其对不同大豆品种叶片叶绿素含量指数、莽草酸含量、SOD活性等生理指标和产量构成的影响。结果表明:喷施农达41%水剂可以降低抗草甘膦大豆RR1、RR2和普通大豆晋大75、晋豆27叶片的叶绿素指数,而抗草甘膦大豆RR1和RR2的降低幅度远小于普通大豆晋大75和晋豆27。抗草甘膦大豆可以忍受较高剂量(7.38kg/hm2)的农达41%水剂,普通大豆晋大75和晋豆27在较低剂量(0.46kg/hm2)时体内莽草酸就大量积累。随着农达41%水剂剂量的增加,抗草甘膦大豆体内的SOD活性也提高,而普通大豆随着剂量的增加,体内SOD活性受到抑制。RR2和RR1分别以农达41%剂量为1.85kg/hm2和0.92kg/hm2时的各产量构成因素值最高,晋大75和晋豆27以0.46kg/hm2时最高。作物不同品种对草甘膦的敏感程度不同,对农达41%水剂的抗性抗草甘膦大豆大于普通大豆,RR2的抗性和RR1相差不大,晋大75(早熟)的抗性和晋豆27(晚熟)相差不大。在这3个生理指标中,叶片莽草酸含量和叶绿素含量指数的变化比SOD活性敏感。

Random complete block design was used to study the impact of spray Roundup 41% aqua on physiological index and yield composition of glyphosate-resistant soybean cultivars （RR1, RR2） and ordinary soybean cuhivars （Jinda75, Jindou27） at two-trifoliolate leaf stage. The chlorophyll content index, shikimic acid content and SOD activity were measured. The results indicated that the chlorophyll content index of four soybean cultivars decreased with increasing the dosage of Roundup 41% aqua, and the decrease degree of RR1 and RR2 were smaller than that of Jinda75 and Jindou27. Jinda75 and Jindou27 were severely injured at 0.46kg/hm^2 ,and the shikimic acid content of RR1 and RR2 at 7.38kg/hm^2 was less than that of Jinda75 and Jindou27 at 0.46kg/hm^2. SOD activity of RR1 and RR2 was increased with the dosage increasing of Roundup 41% aqua, while that of Jinda75 and Jindou27 was decreased. As a whole, the value of yield composition of RR2 was the highest at 1.85kg/hm^2, RR1 at 0.92kg/hm^2, Jinda75 and Jindou27 at 0.46kg/hm^2, respectively. Among these three physiological indexes, shikimic acid content and chlorophyll content index were more sensitive than SOD activity. There were glyphosate- resistance differences between soybean cuhivars. And the glyphosate-resistance soybean had a higher glvphosate-resistance than the ordinary soybean. The glyphosate-resistance for RR1 was slightly stronger than that for RR2, the late-maturing cuhivar of ordinary soybean is slightly stronger than the early-maturing cuhivar. The change of physiological indexes showed differences of glyphosate-resistance for cultivars, and had an important significance production. in breeding and applying glyphosate properly in soybean production.