摘要
研究了番茄夏季不同生长阶段午间遮荫对光合作用、干物质分配和产量构成的影响。结果表明 ,不同时期遮荫使番茄初花期、盛花期和末花期午间气孔导度 (Gs)和胞间CO2 浓度 (Ci)增加 ,75 %遮荫显著降低净光合速率 (Pn) ,但盛花期中度遮荫 ( 40 %遮荫 )的Pn随着遮荫时间的增加逐渐上升 ,在末花期阶段表现尤为明显 ,8d平均Pn比对照增加 2 2 %,蒸腾速率也显著增加。在初花和盛花期 ,重度遮荫 ( 75 %遮荫 )显著降低根、茎干样质量 ,但中度遮荫使末花期的根、茎干样质量分别比对照 (不遮荫 )增加 43 %和 2 2 %,叶干样质量的增加不明显。初花期遮荫对果实产量影响不明显 ,但盛花期 75 %遮荫的总产量和有效产量显著降低 ;在末花期 ,与对照相比 ,40 %的遮荫使总产量和有效产量显著增加 ,单果质量亦增加 35 %。这些结果表明 ,末花期午间适度遮荫有利于提高光合作用 ,增加干样质量和经济产量。
This paper studied the effects of three levels of shading(no shading,75% shading and 40% shading)for 8 days on tomato leaf photosynthesis,dry matter partitioning and yield formation at three growth stages〔i.e.early flowering(EF),peak flowering(PF),late flowering(LF)〕.Different effects caused by shading at different growth stages were found.Shading caused a higher increase in stomatal conductance and intercellular CO 2 concentration at all three growth stages compared with unshaded plants,significantly reduced the midday net photosynthetic rates at most days of the EF stage,but the photosynthetic rates in 40%-shaded leaves at PF stage were increased gradually depending on the length of the shading time.This trend become more obvious and the average photosynthetic rates during a 8-day shading period in 40% shading treated leaves was increased by 22% at the LF stage.The 75% shading treatment reduced the dry mass of root and stem tissues at the EF and PF stages,while the 40% shading region increased root dry mass and stem dry mass by 43% and 22% compared with the unshaded treatment at the LF stage.The influence of shading on the dry mass of leaves was very small at most growth stages.A 40% shading treatment at the LF stage significantly enhanced the fruit yield,but failed to affect the fruit yield at the EF stage.The results showed that tomato could grow well and a better yield could be obtained if some moderate shading(i.e.40% shading)was applied at the LF stage in the summer midday time.
出处
《园艺学报》
CAS
CSCD
北大核心
2002年第5期427-432,共6页
Acta Horticulturae Sinica
基金
国家自然科学青年基金项目 ( 410 710 0 5 )
国家杰出青年科学基金项目 ( 4972 5 10 2 )
烟台师范学院博士引进基金项目
西北农林科技大学青年专项基金项目 (B2 0 0 10 8)
973项目 (G19990 1170 8)
