井窖式移栽对烟苗生长和光合特性的影响

Effects of well-cellar style transplanting on growth and photosynthetic characteristics of flue-cured tobacco seedlings

关键词:  烟苗  移栽方式  井窖式  生长  光合生理

Key words:  tobacco seedling  transplanting  well-cellar style transplanting  growth  photosynthetic physiology

摘要:

为探讨井窖式移栽烟苗生长发育过程中的光合生理变化,结合田间和盆栽试验,对比研究了常规膜上和井窖式2种移栽模式下烟苗生长环境的太阳光合有效辐射(PAR)水平和生长发育水平,进一步分析了烟苗叶片光合作用和光系统Ⅱ(PSⅡ)最大光化学效率(F_v/F_m)特征。结果表明:与常规膜上移栽比较,井窖内太阳光合有效辐射水平降低,其中,井窖内距井窖口4和8 cm处PAR分别为常规移栽的72.60%和52.85%;井窖式移栽提高了烟苗株高、增大了烟叶最大叶长和叶宽,但降低了叶片叶绿素含量;井窖式移栽降低了叶片最大净光合速率(P_max)和光饱和点(LSP),但表观量子效率(AQY)提高了4.44%,光补偿点(LCP)和暗呼吸速率(R_d)分别减小了20.43%和17.78%,增强了烟苗对井窖内弱光的适应能力;井窖式和常规膜上移栽均降低了PSⅡ的最大光化学效率(F_v/F_m),但井窖式移栽烟苗F_v/F_m显著(P<0.05)高于常规膜上移栽,增幅5%~9%。采用井窖式移栽,烟苗对井窖内弱光环境的自我适应和光能利用能力增强,生长发育加快。

Abstract:

The well-cellar style transplanting (WCST) in China was an original transplanting method of flue-cured tobacco, and had obvious comparative advantages when compared to the conventional transplanting (CT).WCST accelerated the growth of tobacco seedlings, so it is necessary to study the characteristics of photosynthetic physiology of tobacco seedlings in WCST.Combined with the field and pot experiments, the study was conducted on photosynthetic active radiation (PAR) level, plant height, leaf length, leaf width and chlorophyll content.The leaf photosynthesis and maximal photochemical efficiency (F_v/F_m) of photosynthetic system Ⅱ (PSⅡ) were analyzed in WCST, compared with CT.The results showed that the photosynthetic active radiation (PAR) levels in WCST were decreased, e.g., the photosynthetic active radiation levels (PAR) were 72.60% and 52.85% at 4 cm and 8 cm in well-cellar respectively, compared with the conventional transplanting (CT).The plant height, leaf length and leaf width of tobacco seedlings were increased, but the leaf chlorophyll contents were reduced in WCST.In WCST, the maximum net photosynthetic rates (P_max) and the light saturation points (LSP) were decreased;the light compensation points (LCP) and dark respiration rates (R_d) were reduced by 20.43% and 17.78% respectively;nonetheless, the apparent quantum yield (AQY) was improved by 4.44%, compared to CT.There was a possibility that the tobacco seedlings were fitted for weak light within well-cellar.PSⅡ maximal photochemical efficiency (F_v/F_m) of tobacco seedlings was reduced when transplanted in WCST or CT, but the F_v/F_m of transplanting seedlings was significantly (P<0.05) higher by 5% to 9% in WCST than in CT.The growth of tobacco seedlings transplanted by well-cellar style transplanting was accelerated in the well-cellar.The self-adaptation and the enhanced light use efficiency in weak light environment are the physiological basis to promote tobacco growth.