不同供硼水平对绿豆植株形态及其叶片生长特征的影响

摘要

利用水培以绿豆为材料,研究不同供硼水平对绿豆植株形态和叶片生长特征的影响.结果表明缺硼抑制绿豆生长,但对根的影响较对冠的影响更大,表现在缺硼导致冠根比增大;缺硼明显抑制叶面积;降低特定叶面积(SLA),这可能是由于缺硼影响细胞伸展的缘故,造成叶片密度增加;缺硼也提高叶片重量比(LWR)并导致叶脉间失绿,说明缺硼叶片可能过量碳水化合物积累,引起叶绿素降解.与适量供硼比较,过量供硼也影响绿豆的生长,但对冠根比没有影响,表明过量供硼对根和冠具有相同的抑制作用;硼中毒导致成熟叶片脱落,从而影响叶面积,但对特定叶面积(SLA)和叶片重量比(LWR)没有影响.%The effects of boron deficiency and toxicity on the morphology and foliar generalities of mung bean (Phaseolus aureus Roxb) were investigated in hydroponic culture. Reduced biomass production in response to limited supply of boron was accompanied by an increased shoot to root ratio. Foliar generalities were also altered by boron deficiency: leaf expansion was inhibited together with specific leaf area (SLA), implying that there was a high leaf cell density due to restricted cell expansion. An increased leaf weight ratio (LWR) and inter-veinal chlorosis evidenced in boron deficient leaves may indicate excessive carbohydrate accumulation, leading to a decline in chlorophyll content. Compared with shoot to root ratio when optimum boron was supplied, high levels of boron did not induce significant changes in shoot to root ratio, suggesting that supra-optimum boron has similar effects on shoot and root growth. Boron toxicity reduced total leaf area by way of abscission of the old leaves, but did not influence SLA or LWR.