彩色遮阳网覆盖对菜心生长及光合特性的影响

Effects of color shading-nets on the growth and photosynthetic characteristics of flowering Chinese cabbage

采用盆栽试验,设红网(遮光率45.0%)、蓝网(遮光率51.1%)、银灰网(遮光率47.2%)、黑网(遮光率47.3%)等4种彩色遮阳网覆盖处理,以不覆盖作为对照,探讨彩色遮阳网覆盖对菜心生长及光合特性的影响。结果表明:与对照不覆盖相比,红网覆盖显著提高了菜心的株高、茎粗、全株鲜质量和叶面积,蓝网、银灰网和黑网覆盖则降低了菜心的生长性状。4种遮阳网覆盖均显著降低了菜心叶片的比叶质量,但增加了叶绿素a、叶绿素b、总叶绿素及类胡萝卜素含量,其中黑网>红网>银灰网>蓝网>对照,叶绿素a/b值均减小。在光照强度0～2 000μmol/(m2.s)范围内,菜心叶片的净光合速率(Pn)随光照强度的增加而升高,各处理间表现为对照≈红网>蓝网>银灰网>黑网。红网覆盖处理菜心的表观量子效率(AQY)较对照增加1.1%,蓝网、银灰网及黑网覆盖处理分别比对照降低30.4%、44.0%和54.2%。红网覆盖通过提高菜心的光合性能显著促进植株生长,适合在生产上推广应用。

The effects of 4 color shading-nets （red：shading rate 45.0%,blue：shading rate 51.1%,grey：shading rate 47.2%,black：shading rate 47.3%） on plant growth and photosynthetic characteristics of flowering Chinese cabbage （Brassica campestris L.ssp.chinensis （L.） var.utilis Tsen et Lee） were studied.The results showed that red-net covering increased plant height,stem diameter,total plant fresh mass and leaf area of flowering Chinese cabbage significantly,while blue,grey and black net covering decreased plant growth characteristics comparing with the control （no shading）.The 4 shading nets covering significantly reduced plant specific leaf mass,while the contents of chlorophyll a,b,total chlorophyll and carotene were increased with the tendency black net〉red net〉grey net〉blue net〉control.The ratio of chlorophyll a/b was decreased by shading treatments compared with the control.In the light density range of 0-2 000 μmol/（m2·s）,net photosynthetic rate （Pn） of flowering Chinese cabbage leaf increased steadily with the increase of light density,and the Pn value among treatments showed control≈red net〉blue net〉grey net〉black net.Apparent quantum yield （AQY） of flowering Chinese cabbage in red-net shading treatment increased by 1.1%,compared with the control,but decreased by 30.3%,44.0%and 54.2% in blue,grey and black net shading treatments,respectively.Red-net shading could promote plant growth of flowering Chinese cabbage significantly by improving its photosynthetic performance,indicating that it was suitable for popularization and application.