播量对直播稻郑旱10号产量及根系生理性状的影响

Effect of Seeding Rate on Yield and Root Physiological Trait of Direct-seeded Rice Zhenghan No.10

以直播稻品种郑旱10号为供试材料,探讨不同播量(90、120、150、180、210 kg/hm2)对直播稻郑旱10号产量及根系生理性状的影响,以期为直播稻适宜播量的选择提供理论依据与指导。结果表明,直播稻郑旱10号的产量随播量增加先显著增加后显著降低,当播量为150 kg/hm2时,产量最高,为10.64 t/hm2。直播稻郑旱10号的叶片净光合速率在齐穗后逐渐下降,随播量的增加先增加后降低,播量为150 kg/hm2时达到最大。地上部干质量随生育进程的推进而增加,根干质量、根系总吸收表面积和活跃吸收面积均随生育进程的推进先增加后降低,齐穗期达到最大;地上部、根干质量和根系总吸收表面积、活跃吸收面积在分蘖中期、穗分化始期和齐穗期均随播量增加而增加,而在成熟期随播量增加先增加后降低,播量为150 kg/hm2时达到最大。根系氧化力和根系生长素、玉米素+玉米素核苷含量均随生育进程的推进先增加后降低,穗分化始期达到最大;均随播量增加而降低,其中齐穗期和成熟期在播量大于150 kg/hm2时,降低更加明显。综上,当播量为150 kg/hm2时,直播稻郑旱10号的叶片净光合速率最大,成熟期地上部、根干质量和根系总吸收表面积、活跃吸收面积最大,根系氧化力、根系生长素、玉米素+玉米素核苷含量较大,产量最高。

The effects of seeding rates（90,120,150,180 ,210 kg/ha）on grain yield and root physiological trait of direct-seeded rice Zhenghan No. 10 , so as to provide theoretical basis for selection of suitable seeding rate of direct-seeded rice. The results showed that grain yield of direct-seeded rice Zhenghan No. 10 increased first and then decreased with the increase of seeding rate, the highest yield was 10. 64 t/ha when seeding rate was 150 kg/ha. The net photosynthetic rate of leaves of direct-seeded rice Zhenghan No. 10 decreased after full heading stage, and increased first and then decreased with the increase of seeding rate,which was the highest when seeding rate was 150 kg/ha. The dry weight of shoots increased with the growth process, and dry weight of root, root absorption area and active absorption area increased with the increase of seeding rate at mid-tillering stage, panicle initiation stage and full heading stage, and increased first and then decreased with the increase of seeding rate at maturity stage, which reached the maximun when seeding rate was 150 kg/ha. The root oxidation activity, root indole-3-acetic acid content, zeatin ＋ zeatin riboside （Z ＋ZR） content increased first and then decreased with the growth p rocess, which reached the maximun at panicle initiation stage,which decreased with the increase of seeding rate,which decreased more obviously when seeding rate were more than 150 kg/ha at full heading stage and maturity stage. In summary,when seeding rate was 150 kg/ha,the net photosynthetic rate of leaves of direct-seeded rice Zhenghan No. 10 was the maximum, the dry weight of shoots and root, root absorption area and active absorption area reached the maximum at maturity stage, root oxidation activity, root indole-3-acetic acid content,Z ＋ ZR content were higher,and grain yield was the highest.