Effects of Three Methanol Extracts from Plant on Stem Properties,Photosynthetic Characteristics and Yield of Wheat

【Objective】 To evaluate the growth regulating activities of methanol extracts from Sophraalopecuroides, Cuminum cyminum and Vallisneria natans on wheat so as to provide experimental and theoretical basis for the development of new plant-derived growth regulators. 【Methods】 Spring wheat variety Xinchun 44 was used as experimental material with water treatment as control; The wheat was sprayed three times in the early stage of wheat jointing by the methanol extracts from Sophraalopecuroides, Cuminum cyminum and Vallisneria natans and prepared into three different solutions with concentrations (1%, 0.1% and 0.01%), respectively. After that, the effects of higher stem properties, photosynthetic characteristics and yield of wheat were analyzed and the extracts with good effect were screened and evaluated by principal component analysis. 【Results】 Compared with the control, after treatment with 0.01% methanol extracts from Vallisneria natans, the length of the 1st, 2nd and 3rd internodes in the base of wheat were decreased by 27.80%, 13.40% and 4.50%, respectively; The stem diameter were increased by 10.30%, 16.10% and 14.30% respectively; The content of IAA in basal 3 sections was increased by 16.16%; The content of ABA in basal 3section was decreased by 7.89%; Plant height was decreased by 5.60%; The net photosynthetic rate of flag leaves was increased by 3.90%; The SPAD value of flag leaves was increased by 6.20%; 1,000-grain weight, grain weight and bulk density were increased by 2.82%, 24.69% and 3.64%, respectively. Principal component analysis showed that the effect of the treatment with 0.01% methanol extracts from Vallisneria natans was significantly better than those of other treatment groups. 【Conclusion】 Three low concentration methanol extracts from Sophraalopecuroides, Cuminum cyminum and Vallisneria natans have different growth regulation effects on wheat, which can shorten the internode length and increase the stem diameter, can enhance the lodging resistance of wheat, can also reduce the plant height of wheat, and can improve the ventilation and light transmission conditions in the field thus improving the photosynthesis of flag leaves, the utilization rate of light energy as well as the yield of crops. Among them, the treatment effect of 0.01% methanol extracts from Vallisneria natans is the best.