遮光处理对不同生育期小麦生物量分配和叶片叶绿素含量的影响

Effect of shading on biomass allocation and chlorophyll content in leaf of Triticum aestivum at different developmental stages

以普通小麦‘扬麦12号’(Triticum aestivum‘Yangmai12’)为实验材料,研究了遮光处理对不同生育期小麦生物量分配和叶片叶绿素含量的影响。结果显示,从拔节期到完熟期,在不同遮光条件下(对照:相对透光率为100%;T1:相对透光率约为80%;T2:相对透光率约为60%;T3:相对透光率约为20%),小麦地上部分、地下部分及全株干质量随着发育期的延续总体呈增加趋势。遮光处理使小麦地上部分和地下部分干质量较对照不同程度降低,其中遮光对地上部分干质量的影响大于地下部分,并且根冠比随遮光程度的增加而增大。从开花期开始,各个生育期T3处理组小麦的根冠比均为最大,对照组小麦的根冠比均为最小。‘扬麦12号’地上部分和地下部分异速生长关系为简单的线性异速生长模型,遮光后小麦的异速性减小,按小麦地上部分和地下部分间的异速性由大至小依次排序为对照组、T1处理组、T2处理组、T3处理组。从抽穗期到乳熟期,对照及各处理组小麦叶片的叶绿素a、叶绿素b及总叶绿素含量在灌浆期(或乳熟期)最高;在不同的生育期,不同遮光处理对小麦叶片中叶绿素a、叶绿素b及总叶绿素含量的影响不同,随着遮光程度的增加,各遮光处理组小麦的叶绿素a/b均不同程度低于对照。

Effect of shading on biomass allocation and chlorophyll content in leaf of Triticum aestivum L. at different developmental stages was researched using T. aestivum ＇Yangmai 12＇ as experimental material. The results show that from jointing stage to ripe stage,the dry weight of above-ground and under-ground parts,whole plant of T. aestivum ＇Yangmai 12＇ increases under different shading conditions （control：natural light with 100% available light; T1：available light about 80%; T2：available light about 60%; T3：available light about 20%） with developmental stage postponing. The dry weight of above-ground and under-ground parts under shading conditions is lower than that under control with different degrees. The effect of shading on dry weight of above-ground part is stronger than that on dry weight of under-ground part,and root/shoot ratio increases with shading degree increasing. From flowering stage,root/shoot ratio of ＇Yangmai 12＇ in T3 treatment group at each developmental stage is all the biggest and that in control is the smallest. Allometric growth relationship of above-ground and under-ground parts of ＇Yangmai 12＇ is a simple linear allometric model,and allometric growth of ＇Yangmai 12＇ decreases after shading. According to allometric growth of above-ground and under-ground parts from big to small,the order is control,T1,T2,T3,successively. From heading stage to milky stage,contents of chla,chlb and chla＋chlb in ＇Yangmai 12＇ leaf in control and three treatment groups all are the highest at filling or milky stages. Different shading treatments have different effects on contents of chla,chlb and chla＋chlb in ＇Yangmai 12＇ leaf at different developmental stages,and with shading degree increasing,chla/chlb ratio in shading conditions is lower than that in control with different degrees.