小麦旗叶叶脉特征对水氮供应的响应及其与叶水力生理功能的关系  

Responses of flag-leaf vein traits to nitrogen and water supplies and their correlations with leaf hydraulic-physiological function in wheat

作　　者：徐慧敏 邵景侠[2] 李秧秧 XU Hui-min;SHAO Jing-xia;LI Yang-yang(College of Forestry,Northwest A&F University,Yangling,Shaanxi 712100,China;College of Life Sciences,Northwest A&F University,Yangling,Shaanxi 712100,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau/Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100 [2]西北农林科技大学生命科学学院,陕西杨凌712100 [3]黄土高原土壤侵蚀与旱地农业国家重点实验室/西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《植物营养与肥料学报》2020年第9期1636-1646,共11页Journal of Plant Nutrition and Fertilizers

基　　金：“十二五”国家科技支撑计划课题(2015BAD22B01)。

摘　　要：【目的】环境条件直接影响叶脉特征及其与叶生理功能的关系,研究不同氮、水有效性下小麦叶脉系统的可塑性变化及其与叶生理功能的关系,对于揭示其对不同生境的适应性有重要价值。【方法】采用三因素完全随机试验设计的盆栽试验,设置2个品种:水地品种郑麦101和旱地品种长旱58;2个氮肥处理水平:不施氮和底施N 0.15 g/kg干土;3个水分处理水平:拔节期土壤含水量分别降至田间持水量的70%~75%、50%~55%、30%~35%,并维持3周。主要测定了小麦旗叶叶脉特征[主脉密度(VLAm a j o r)、细脉密度(VLAminor)、叶脉密度(VLA)和细脉所占比例(Prominor)]和叶水力生理功能参数[叶水力导度(Kleaf)、净光合速率(Pn)、气孔导度(gs)、蒸腾速率(E)及瞬时水分利用效率(IWUE)]。【结果】长旱58旗叶的VLAmajor、VLAminor、VLA和Prominor高于郑麦101。随着氮肥或水分供应增加,两个品种的VLAmajor均出现降低趋势,郑麦101的VLAminor和VLA变化不大,而长旱58的VLAminor和VLA均降低,两个小麦品种的VLAminor和VLA对氮肥和水分表现出不同的反应。在4个叶脉特征与5个叶生理功能的相关关系中,郑麦101有5组达到显著(P<0.05)或接近显著(0.05<P<0.1),即VLAmajor与Kleaf、gs呈负相关,Prominor与Kleaf、gs及E呈正相关;长旱58有14组达到显著或接近显著,即VLAmajor、VLAminor和VLA均与Kleaf、Pn和gs呈负相关,VLAmajor与IWUE呈负相关,VLAminor和VLA与E呈负相关,Prominor与Pn、E呈负相关。【结论】旱地品种长旱58叶脉特征对水氮供应表现出更高的可塑性,且叶脉特征和叶生理功能的联系更为紧密;水地品种郑麦101叶水力生理功能随细脉所占比例增加而增加,而旱地品种长旱58叶水力生理功能受叶脉密度和细脉所占比例的直接制约,这表明不同级别叶脉长度所占比例的优化是水地品种叶水力功能提升的一个重要原因,而木质部导管直径和木质部以外水力导度对�【Objectives】Leaf vein traits affect leaf physiological function.We studied the plastic response of the leaf vein traits to different nitrogen and water supplies,and analyzed their correlation with leaf physiological function for demonstrating plant adaptation to different habitats.【Methods】A pot experiment with a threefactor complete random design was conducted.The two wheat cultivars were drought-sensitive Zhengmai 101 and drought-tolerant Changhan 58;the two nitrogen fertilizer levels were 0 and N 0.15 g/kg dry soil before sowing;the three water supplying levels were 70%–75%,50%–55%and 30%–35%of field capacity at the jointing stage,respectively.After the water treatments were maintained for about 3 weeks,the flag-leaf vein traits[major-vein density(VLAmajor),minor-vein density(VLAminor),vein density(VLA)and proportion of minorvein density(Prominor)],and the leaf hydraulic-physiological function indices[leaf hydraulic conductance(Kleaf),net photosynthetic rate(Pn),stomatal conductance(gs),transpiration rate(E)and instantaneous water use efficiency(IWUE)]were measured.【Results】Drought-tolerant cultivar Changhan 58 had higher VLAmajor,VLAminor,VLA and Prominor than drought-sensitive cultivar Zhengmai 101.For Zhengmai 101,VLAmajor decreased,VLAminor and VLA kept unchanged with the increased nitrogen and water supplies,whereas for Changhan 58,VLAmajor,VLAminor and VLA all decreased with the increased nitrogen and water supplies.VLAminor and VLA of two wheat cultivars showed different responses to N and water supplies.In the twenty correlations between leaf vein traits and leaf hydro-physiological function parameters,five ones of Zhengmai 101 reached significant(P<0.05)or nearly significant levels(0.05<P<0.1),VLAmajor was negatively correlated with Kleaf and gs,and Prominor was positively correlated with Kleaf,gs and E.And for Changhan 58,14 correlations were significant or nearly significant,VLAmajor,VLAminor and VLA were all negatively correlated with Kleaf,Pn and gs,VLAmajor were negatively corre

关 键 词：小麦 叶脉特征 氮肥 水分 叶水力生理功能 

分 类 号：S512.1[农业科学—作物学]