不同刈割程度对油莎豆非结构性碳水化合物代谢及生物量的影响

为探讨不同留茬高度对油莎豆(Cyperus esculentus)非结构性碳水化合物代谢的影响,进一步明确不同留茬高度与油莎豆地上生物量的关系,并寻求最佳刈割高度,该研究以油莎豆为研究对象,测定6个留茬高度(10、20、30、40、50 cm和未刈割)油莎豆叶片生长生理参数、非结构性碳水化合物含量和地上生物量。结果显示:刈割对于油莎豆光合作用有刺激作用,刈割后油莎豆在第1–14天达到再生生长高峰期。留茬30cm油莎豆叶片可溶性糖含量(第7、21和28天)均高于其他处理,分别为9.22%、10.83%、9.07%,其淀粉含量(第14和21天)均高于其他处理,分别为4.88%和4.11%。留茬40 cm (第21、28天)蔗糖含量均高于其他处理,分别为7.88%和11.38%;其果糖含量(第14和21天)均高于其他处理,分别为5.29%和6.40%。刈割促进了留茬30和40cm油莎豆叶片蔗糖磷酸合成酶和蔗糖合成酶活性的提高。留茬10cm抑制了油莎豆叶片蔗糖含量增加和相关酶活性。合计刈割时和收获时的饲草质量之和,留茬30cm油莎豆干草质量最高,为10 605.11kg·hm^-2

Effects of different clipping degrees on non-structural carbohydrate metabolism and biomass of Cyperus esculentus

Aims The aims of this study were to investigate the effects of different stubble height on non-structural carbohydrate metabolism of Cyperus esculentus, to further clarify the relationship between stubble height and aboveground biomass of C. esculentus, and to seek the best clipping height.Methods The growth physiology parameters, non-structural carbohydrates and aboveground biomass of C. esculentus leaves at six stubble heights (10, 20, 30, 40, 50 cm and uncut) were determined.Important findings The results showed that clipping can stimulate the photosynthesis of C. esculentus. The peak of regeneration and growth was reached from 1 to 14 days after clipping. The contents of soluble sugars in leaves of 30 cm stubbles (7th, 21st and 28th days) were higher than those in leaves of other treatments, which were 9.22%, 10.83% and 9.07%, respectively, and the starch contents (14th and 21st days) were 4.88% and 4.11%, respectively. The sucrose contents in leaves of 40 cm stubbles (21st and 28th days) were higher than those in leaves of other treatments, which were 7.88% and 11.38%, respectively. The fructose contents (14th and 21st days) were also higher than those in leaves of other treatments, which were 5.29% and 6.40%, respectively. The activities of sucrose phosphate synthase and sucrose synthase in 30 cm stubbles and 40 cm stubbles were higher than those in other treatments in different periods after clipping. Stubble 10 cm inhibited the increase of sucrose content and related enzyme activities of C. esculentus. The total amount of forage at clipping and harvest, the hay mass of 30 cm stubbles was up to 10 605.11 kg·hm^-2, 19.93% higher than that of uncut. The hay mass of 40 cm stubbles was up to 8 976.93 kg·hm^-2, 1.52% higher than that of uncut. In addition, through redundancy analysis, soluble sugar content, the activities of sucrose synthase and sucrose phosphate synthase were important factors affecting the forage yield and regeneration rate. In the long period of cutting (day 7-28), 30-40 cm stubbles were more conducive to regeneration and growth, accumulation and synthesis of non-structural carbohydrate, as well as related enzyme activities and forage yield. Therefore, the suitable stubble height range was 30-40 cm.