不同抗性稗草对水稻产量及其生理特性的影响

为探讨对除草剂敏感的稗草和产生多抗性的稗草对水稻生长发育的影响,以南粳9108为试验材料,自水稻移栽至成熟分别与对二氯喹啉酸、稻杰和双草醚均敏感的稗草(敏感稗草,T1)和对二氯喹啉酸、稻杰和双草醚均产生抗性的稗草(多抗性稗草,T2)共生,以无稗草水稻处理为对照(CK)。结果表明,与T1相比,T2的分蘖数、干物质积累量和每穗粒数显著降低、生育期缩短,但千粒重显著增加。与稗草共生后,与CK相比,T1和T2的水稻产量分别显著减产32.5%~33.4%和24.8%~26.7%,T2的减产率略低于T1,但二者差异不显著。与CK相比,T1和T2还显著降低了水稻抽穗期水稻叶面积指数、灌浆期叶片光合速率、根系氧化力、根干重、籽粒中玉米素+玉米素核苷、吲哚-3-乙酸含量、蔗糖合成酶和腺苷二磷酸葡萄糖焦磷酸化酶活性和成熟期干物质积累量,T1与T2间差异不显著。水稻叶面积指数、灌浆期叶片光合速率、根系氧化力、根干重、籽粒中玉米素+玉米素核苷、吲哚-3-乙酸含量、蔗糖合成酶和腺苷二磷酸葡萄糖焦磷酸化酶活性和成熟期干物质积累量的显著降低是T1和T2致使水稻产量降低的重要原因。本研究结果为杂草综合治理和水稻高产栽培提供了理论依据。

Effects of Barnyardgrass With Different Resistance on Grain Yield of Rice and Their Physiological Characteristics

In order to investigate the growth and development effects of susceptible and resistant barnyardgrass on rice,two barnyardgrass varieties (susceptible for T1 and resistant for T2) separately against quinclorac,penoxsulam and bispyribac-sodium,were employed under the co-culture condition with rice nanjing 9108 during the period from rice transplanting to maturity and with weed free as a CK.The results showed that resistant barnyardgrass significantly reduced tiller number,dry matter accumulation,spikelets per panicle and shorted growth period,but increased the 1 000-grain weight when compared with susceptible-herbicide barnyardgrass.After co-cultured with barnyardgrass,compared with CK,both treatments of T1 and T2 significantly reduced the grain yield of rice for by 32.5％ ～ 33.4％ and 24.8％ ～ 26.7％,respectively.The lose rate in rice grain yield of T2 was slightly lower than T1,but statistical analysis showed no significant difference was observed between T1 and T2.Furthermore,T1 and T2 substantially reduced LAI at heading stage,flag leaf photosynthetic rate,root oxidation activity,dry root biomass,contents of zeatin + zeatin riboside,activities of sucrose synthase and adenosine diphosphate glucose pyrophosphorylase in grains during grain filling stage and dry matter accumulation at maturity stage of rice as comparison with CK.Moreover,there was no significant difference as above described parameters between T1 and T2 treatments.In conclusion,all results preliminary detected the decrease in flag leaf photosynthetic rate,root oxidation activity,dry root biomass,contents of zeatin + zeatin riboside,activities of sucrose synthase and adenosine diphosphate glucose pyrophosphorylase in grains during grain filling stage and dry matter accumulation in maturity of rice might be the important reasons for rice loss when co-cultured with barnyardgrass.The above results provide a theoretical evidence for high yield cultivation of rice and integrated weed management.