水保所知识产出(1956---)知识库

【 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 (VLA major )、细脉密度
(VLA minor )、叶脉密度 (VLA) 和细脉所占比例 (Pro minor )]和叶水力生理功能参数[叶水力导度 (K leaf )、净光合速率
(P n )、气孔导度 (g s )、蒸腾速率 (E) 及瞬时水分利用效率 (IWUE)]。 【 结果】 长旱 58 旗叶的 VLA major 、VLA minor 、
VLA 和 Pro minor 高于郑麦 101。随着氮肥或水分供应增加，两个品种的 VLA major 均出现降低趋势，郑麦 101 的
VLA minor 和 VLA 变化不大，而长旱 58 的 VLA minor 和 VLA 均降低，两个小麦品种的 VLA minor 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 VLA major 与 K leaf 、g s 呈负相关，Pro minor 与 K leaf 、g s 及 E 呈正相关；长旱 58 有 14 组达
到显著或接近显著，即 VLA major 、VLA minor 和 VLA 均与 K leaf 、P n 和 g s 呈负相关，VLA major 与 IWUE 呈负相关，
VLA minor 和 VLA 与 E 呈负相关，Pro minor 与 P n 、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
度对旱地品种叶水力生理功能的影响更大。

【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 three-
factor 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 thejointing stage, respectively. After the water treatments were maintained for about 3 weeks, the flag-leaf vein
traits [major-vein density (VLA major ), minor-vein density (VLA minor ), vein density (VLA) and proportion of minor-
vein density (Pro minor )], and the leaf hydraulic-physiological function indices [leaf hydraulic conductance (K leaf ), net
photosynthetic rate (P n ), stomatal conductance (g s ), transpiration rate (E) and instantaneous water use efficiency
(IWUE) ] were measured. 【Results】 Drought-tolerant cultivar Changhan 58 had higher VLA major , VLA minor , VLA
and Pro minor  than drought-sensitive cultivar Zhengmai 101. For Zhengmai 101, VLA major  decreased, VLA minor  and
VLA kept unchanged with the increased nitrogen and water supplies, whereas for Changhan 58, VLA major , VLA minor
and VLA all decreased with the increased nitrogen and water supplies. VLA minor  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), VLA major  was negatively correlated with K leaf  and g s , and Pro minor  was positively
correlated with K leaf , g s  and E. And for Changhan 58, 14 correlations were significant or nearly significant,
VLA major , VLA minor  and VLA were all negatively correlated with K leaf , P n  and g s , VLA major  were negatively correlated
with IWUE, VLA minor  and VLA were negatively correlated with E, and Pro minor  was negatively correlated with P n
and E. 【Conclusions】 Leaf vein traits of drought-tolerant wheat cultivar are sensitive to nitrogen and water
supplies, and more closely correlated with leaf hydraulic-physiological functions. Leaf hydraulic-physiological
functions will be increased with the higher proportion of minor-vein length in drought-sensitive cultivar, while
they will be constrained by vein density and proportion of minor-vein length in drought-tolerant cultivar,
suggesting that drought-sensitive cultivar increase its leaf hydraulic-physiological function through optimization
of vein length of different types of veins, and the drought-tolerant wheat cultivar through enlarged conduit
diameter and extra-xylary hydraulic conductance.