低温胁迫下裂殖壶菌藻粕对花生种子萌发和幼苗生长的影响

Effects of Schizochytrium Algae Meal on Germination and Growth of Peanut under Low Temperature Stress

花生是我国重要的经济和油料作物,倒春寒等低温冷害严重影响我国北方春花生产区的花生发芽和出苗率。裂殖壶菌(Schizochytrium sp.)是二十二碳六烯酸(Docosahexaenoic acid,DHA)商业化生产的代表性菌种之一,为使裂殖壶菌提取DHA后的废弃物藻粕能够被利用,本研究以青花11号花生品种为供试材料,两种不同浓度的裂殖壶菌藻粕稀释液施用为处理,分别在恒定4℃和昼夜交替(19℃/4℃)的低温环境下,测定花生种子萌发和生理相关指标。结果发现:与正常温度条件相比,低温胁迫降低了花生下胚轴长、根长、苗长和干物质积累量。在两种低温处理下,施用了藻粕液的花生种子露白率和出苗率均显著增加15%以上,干物质量、根长、苗长及下胚轴长度也均显著高于对照组;在4℃持续低温下,随着胁迫时间的延长,各处理的丙二醛(MDA)含量不断增加,藻粕液处理的花生胚芽中MDA含量显著降低,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均有上升,过氧化氢酶(CAT)活性先下降后上升,且三种酶活性都显著高于对照。本研究表明,施用裂殖壶菌藻粕对花生种子在冷害发生时起到了一定的保护作用,将为花生种子缓解倒春寒胁迫及裂殖壶菌藻粕的资源高效再利用提供解决方案,也为开发新一代的花生种子包衣剂提供了理论基础。

Peanut is an important economic and oilseed crop in China,and cold damage,such as cold snap during the spring severely affects the germination and emergence rate of peanut in most peanut planting areas in China.Schizochytrium sp.is one of the representative strains for the commercial production of docosahexaenoic acid(DHA).In order to utilize the algal meal waste after DHA extraction from Schizochytrium sp.,in present study,the seed germination and physiological indexes of peanut seedlings were conducted using peanut variety Qinghua11 as test material and two different concentrations of Schizochytrium sp.algal meal solution as treatments under constant temperature of 4℃and alternative temperature of day-night(19℃/4℃),respectively.The results showed that seed germination and physiological indexes were determined in the two low temperature treatments,compared to the normal temperature condition,low temperature stress reduced hypocotyl length,root and seedling length,and dry matter accumulation of peanut.Peanut germination and seedling emergence rate significantly increased by more than 15%under the two low temperature treatments with algal meal solution.The dry mass,root length,seedling length,and hypocotyl length were all significantly higher than those of the control group.Under the low temperature of 4℃,the malondialdehyde(MDA)content of each treatment began to increase with increasing duration of stress time,and the MDA content of peanut sprout treated with algal meal solution was significantly reduced,and the activities of superoxide dismutase(SOD)and peroxidase(POD)increased,and the activity of catalase(CAT)firstly decreased and then increased,the activities of all three enzymes were significantly higher than the control group.The study showed that algal meal has a certain protective effect on peanut seed when cold damage occurs,which provides a solution for peanut seed to alleviate the stress of cold snap in the spring and the efficient reuse of Schizochytrium algal meal,and also provided a theoretical basis for the development of a new generation of peanut seed-dressing agent.