放线菌剂使用方法对晚播冬小麦生长及光合性状的影响

为探究放线菌剂使用方法对晚播冬小麦生长及光合性状的影响，以长6990为供试小麦品种、娄彻氏链霉菌（D74）为供试菌剂，在大田设置T1（种子包衣+拔节期、灌浆期喷施D74菌剂）、T2（种子包衣+拔节期喷施D74菌剂，灌浆期喷施清水）、T3（种子包衣+拔节期、灌浆期喷施清水）、T4（种子不包衣+拔节期、灌浆期喷施D74菌剂）和CK（种子不包衣+拔节期、灌浆期喷施清水）5个处理（包衣中含有菌剂D74），比较分析了不同处理间小麦产量及其构成要素、表型性状、光合特性及干物质积累的差异。结果表明，放线菌剂处理下晚播小麦的产量较CK均不同程度提高，增产幅度为7.35%~25.00%，且不同处理的产量表现为T4>T1>T2>T3>CK，其中T1、T4处理与CK差异显著(P＜0.05)；不同处理间株高无显著差异(P>0.05)， T1和T4处理的穗长、穗粒数和千粒重显著高于CK，T2处理穗粒数和千粒重也较高。在光合性状中，放线菌剂处理主要影响晚播小麦灌浆后期的光合效率。花后28~35 d，T1、T4处理的旗叶净光合速率，T1~T4处理的旗叶叶绿素相对含量（SPAD）和氮含量，T1、T2和T4处理的叶面积指数均显著高于CK。放线菌剂使用后晚播小麦的花前干物质转运量及其对籽粒产量贡献率有所降低，但不同处理间差异不显著。T1、T2和T4处理的花后干物质的积累量较CK增加了37.93%、29.42%和50.92%；花后干物质积累对籽粒产量贡献率也有所提高，但不同处理间差异不显著。综合来看，放线菌剂能够有效增加晚播小麦的光合持续能力，延缓叶片衰老，促进花后干物质积累、穗部发育和籽粒灌浆，增加穗粒数和千粒重，进而提高产量，其中放线菌剂种子包衣效果不明显，叶面喷施放线菌剂效果较突出，拔节期和灌浆期叶面喷施放线菌剂的效果最佳。

Effects of Different Application Methods of Actinomycetes on Growth and Photosynthetic Characteristics of Late-Sown Winter Wheat

In order to explore the effects of different application methods of actinomycetes on growth and physiological characteristics of late-sown winter wheat, using Chang 6990 as the test variety and Streptomyces roche (D74) as the test microbial agent, five treatments were set up in the field: T1(seed coating plus spraying D74 at jointing and filling stage), T2 (seed coating plus spraying D74 at jointing stage and clean water at filling stage), T3 (seed coating plus spraying clean water at jointing and filling stage), T4 (spraying D74 at jointing and filling stage without seed coating), and CK (spraying clean water at jointing and filling stage without seed coating). The differences of wheat yield and its components, phenotypic traits, photosynthetic characteristics and dry matter accumulation among the treatments were compared and analyzed. The results showed that the yield of late-sown wheat treated with actinomycetes increased in different degrees by 7.35%-25.00% compared with that of CK, ranking as T4>T1>T2>T3>CK, among which T1 and T4 showed significantly higher yield than CK did (P<0.05). There were no significant differences in plant height among different treatments (P>0.05), and the panicle length, grains per spike, and 1 000-grain weight of T1 and T4 were significantly higher than those of CK, while the grains per spike and 1 000-grain weight of T2 treatment were also higher. The application of actinomycetes mainly affected the photosynthetic efficiency of late-sown wheat at the late filling stage. From 28 d to 35 d after anthesis, the net photosynthetic rate of flag leaf of T1 and T4, the relative content of chlorophyll (SPAD) and nitrogen content of flag leaf of T1, T2, T3 and T4, and the leaf area index of T1, T2, and T4 were significantly higher than those of CK. The dry matter translocation amount before anthesis and the contribution rate of dry matter translocation amount before anthesis to grains of late-sown wheat decreased after using actinomycetes, yet the differences among treatments were not significant. The dry matter accumulation amount after anthesis in T1, T2, and T4 was increased significantly by 37.93%, 29.42%, and 50.92% compared with that of CK. The contribution of dry matter assimilation amount after anthesis to grain also increased, yet there were no significant differences among treatments. Based on the comprehensive analysis, the use of actinomycetes effectively increased the photosynthetic sustainability of late-sown wheat, delayed leaf senescence, improved dry matter accumulation after anthesis, promoted ear development and grain filling, increased the grains per spike and 1 000-grain weight, and thus increased the yield. Among the treatments, the effect of seed coating with actinomycetes was not obvious, while the effect of spraying actinomycetes on the leaf surface was outstanding. Spraying actinomycetes on leaves at jointing and filling stage had the best effect.