壳聚糖类有机水溶肥对杭白菊苗期生长影响及其机制研究

有机种植杭白菊对提高其品质具有重要作用,壳聚糖有机水溶肥作为一种新型的有机肥料在果蔬上已有广泛应用,其在有机杭白菊苗期的最佳用量及其促进苗期生长的作用机制尚不清楚。本研究采用盆栽试验,设置不施肥(CK)、壳聚糖有机水溶肥稀释液1 000倍(T1)、500倍(T2)、300倍(T3)、100倍(T4)5个处理,分析了各处理对杭白菊生物量、生长发育指标、根系形态特征、光合作用、碳氮含量及碳氮比的影响。结果表明:与CK相比,T3处理根鲜重、地上部鲜重、叶片数、茎粗和株高分别显著增加了64%、110%、27%、17%和32%,表明壳聚糖类有机水溶肥稀释300倍是有机杭白菊苗期最佳用量。此外,与CK比,T3处理总根长、根表面积、根体积分别提高了46%、62%和69%,光合速率约增加64%,且调节了杭白菊苗期的碳氮比例,根系与地上部的碳氮比值分别为19和17。综上,改善杭白菊苗期根系的形态特征,增强光合作用,调节植株的碳氮比可能是壳聚糖有机水溶肥促进有机杭白菊苗期生长的机制之一。

Effects and Mechanism of Chitosan Organic Water-soluble Fertilizer on Growth of Chrysanthemum

Chrysanthemum under organic cultivation plays an important role in improving its quality. Chitosan organic water-soluble fertilizer, as a new organic fertilizer, has been widely used in fruits and vegetables. In this study, 5 treatments of no fertilizer (CK), chitosan organic water-soluble fertilizer diluents (1000x (T1), 500x (T2), 300x (T3), and 100x (T4) were set in pot experiment. The effects of each treatment on biomass, growth and development index, root morphological characteristics, photosynthesis, carbon and nitrogen content and carbon and nitrogen ratio of chrysanthemum were analyzed. The results showed that compared with CK treatment, the fresh weight of root, fresh weight of aboveground, leaf number, stem diameter and plant height of T3 treatment significantly increased by 64%, 110%, 27%, 17% and 32%, respectively, which indicated that the optimum amount of organic chrysanthemum seedling was 300 times diluted by organic water-soluble fertilizer of chitosan. In addition, compared with CK, the total root length, root surface area and root volume of T3 treatment increased by 46%, 62% and 69%, and the photosynthesis rate increased by 64%, and the carbon and nitrogen ratio in the seedling stage of chrysanthemum was adjusted, and the carbon and nitrogen ratio in the root system and the aboveground part was 19% and 11%, respectively. In conclusion, improving root morphological characteristics, enhancing photosynthesis and regulating plant carbon and nitrogen ratio may be one of the mechanisms of chitosan organic water-soluble fertilizer to promote the growth of organic chrysanthemum in seedling stage.