不同灌溉方式对旱区葡萄脯氨酸及渗透胁迫相关基因的影响

The Effects of Irrigation Methods on Proline and Osmotic Stress-Related Genes of Grape(Vitis vinifera L.cv.Moldova)in Arid Regions

【目的】评估不同灌溉方式的适用性。【方法】以摩尔多瓦葡萄为试验材料,试验设置6个处理,分为2组。不同灌溉方式(灌溉水量相同),即常规沟灌(CK1)、滴灌(D)和超纤埋深渗灌(超纤毛细芯埋深10 cm)(C);不同水分梯度的超纤表面渗灌(超纤毛细芯放置土壤表面),即普通灌溉量(CK2);普通灌溉量的1/3(W1),低灌溉量;普通灌溉量的2/3(W2),中灌溉量。通过测量土壤含水率、叶水势、果实脯氨酸量、P5CS基因的相对表达量及产量,比较了6个处理下的摩尔多瓦葡萄受旱情况及各种指标。【结果】不同灌溉方式下,CK1受旱时间最多,约占总时间的73%,C处理和D处理分别为67%和40%,同时,CK1脯氨酸量一直大于D处理,且产量、总用水效率及灌溉水利用效率均为C处理>D处理>CK1。不同水分梯度下,葡萄受旱情况差异不显著,另外,5次采样中,有4次W2处理脯氨酸量均明显高于CK2,且分别为CK2的1.5、1.1、1.1、1.8倍,且总用水效率及灌溉水利用效率均为W1处理>W2处理>CK2。不同灌溉方式下,D处理维持土壤含水率的能力最强,C处理土壤含水率适中的时间最多,且D处理和C处理水分利用效率均大于CK1,表明超纤埋深渗灌和滴灌都是较好的节水灌溉方式;不同水分梯度下,W1处理在某些阶段的P5CS基因相对表达量是6种处理中最高的,显示该处理下葡萄受到的水分胁迫较严重,但其产量和水分利用效率较高。【结论】因此,“超细纤维”渗灌在保持土壤有效含水量方面体现出了优越性和应用价值,是一种较优的灌溉方式。

【Objective】Metabolic activities and the genes coding them are modulated by soil water,and the aim of this paper is to study how a new irrigation technology-microfiber capillary core infiltration irrigation(MII)–affects soil water content,leaf water potential,expression of proline-and osmotic stress-related genes of grape in comparison with conventional irrigation methods.【Method】We used the Moldovan variety(Vitis vinifera L.cv.Moldova)as the model plant and conducted the experiment from May to September in 2019 in Yuquanying Farm at the eastern foot of Helan Mountain in Ningxia province.We compared three irrigation methods:conventional ditch irrigation(CK1),drip irrigation(D),and the new microfiber capillary core infiltration irrigation by burying the fibers at the depth of 10 cm;the irrigation amount in all of them was the same.To study the efficacy of MII in saving water,we also laid the capillary fibers over the soil surface and compared three irrigation accounts:the amount used in conventional irrigation(CK2),and reducing it by 2/3(W1)and 1/3(W2)respectively.In each treatment,we measured soil water content,leaf water potential,proline content of the fruits,and relative expression of P5CS genes.【Result】All treatments resulted in water stress though the degree of the stress varied.The water stress in CK1 was most severe persisting in 73%of the growing season,followed by C and D with the crop in the former and the latter suffering from water stress in 67%and 40%of its growth season respectively.The effects of the irrigation method on fruit yield,water use efficiency and irrigation water use efficiency were ranked in the order of C>D>CK1,and in the middle and later growth stage,the soil water content in C and D was higher than that in CK1.For MII,we did not find difference in water stress between the three irrigation amounts at significant level.The leaf water potential in CK1 was less than that in D,meaning that CK1 was more likely to have given rise to water stress,while its proline content was greater than that in D.For all data we measured,the leaf water potential was least in CK1 and largest in D,with that in C in between.Under different irrigation amounts in MII,the leaf water potential was ranked in the order of W2<W1<CK2 for data measured from July 13 to August 22,where the proline content in W2 was 1.1 to 1.8 times that that in CK2,depending on the sampling time.The y ield,water use efficiency and irrigation water use efficiency were ranked in the order of W1>W2>CK2.Coding proline synthesis,the content of P 5 CS gene reflects the water stress and their relative expression in CK1 was significantly higher than those in D and C only from 4 to 28 August.Outside this window,there was no insignificant difference between them based on the data measured on July 25 and September 4.【Conclusion】W ater use efficiency of D and MII was higher than that of CK1,indicating both microfiber infiltration irrigation and drip irrigation s were water-saving.Among all treatments,t he relative expression of P 5 CS gene was the highest in W1,indicating grapes in this treatment had been subject ed to serious water stress despite achieving high yield and water use efficiency.Therefore,the superfine fiber infiltration is an improved irrigation method for grape production in arid regions as studied in this paper.