摘要
为探索不同土壤含水量对黑莓光合特性的影响,以盆栽美国黑莓2～3年生扦插植株为试材,在6种土壤相对含水量(SRWC)条件下,对其光合特性进行研究。结果表明,土壤相对含水量为100%时,叶片净光合速率日变化呈单峰曲线;随着土壤含水量的降低,其净光合速率日变化呈双峰曲线。美国黑莓的光补偿点为50μmol/m2·s左右;SRWC为25%时,其光饱和点仅为330μmol/m2·s;SRWC为70%以上时,光饱和点均为1280μmol/m2·s左右。叶片的净光合速率及蒸腾速率随SRWC的升高而增加,气孔阻力随SRWC的升高而降低。水分利用率随着SRWC的降低而提高,呈极显著的负相关;新梢生长对土壤水分极为敏感。净光合速率与蒸腾速率呈显著正相关,与气孔阻力呈极显著负相关;蒸腾速率与气孔阻力呈显著负相关。美国黑莓的光合作用最适SRWC为85%;灌溉的临界SRWC为40%。
year-old potted grown plants raised by cutting of America black raspberry cutting were used as materials for studying the photosynthesis characters of black raspberry under conditions of six artificial controlled drought gradients.The result showed under the different conditions of soil relative water content ,when SRWC was100%,the curve of diurnal variation of black raspberry leaf photosynthesis showed single peak,with the soil relative water content dropping.The curve of diurnal variation of leaf photosynthesis showed two peaks appeared at9:00and15:00respectively the light compensation point of photosynthesis of black raspberry leaves were50μmol/m 2 ·s;when SRWC were25%,the light saturation point were330μmol/m 2 ·s,when the SRWC 70%and over the light saturation point were1280μmol/m 2 ·s.The leaf net photosynthesis(Pn)rate and transpiration rate increased with the raise of SRWC ,the stoma resistance dropped with the raise of SRWC.The water use efficiency(WUE)raised with the dropping of SRWC.The shoot growth was the most sensitive to SRWC.Positive correlation appeared between the net photosynthetic rate and transpiration rate.There was a significant negative correlation between Pn and the stoma resistance.Negative correlation between the transpiration rate and the stoma resistance also ex-isted.The optimum SRWC of Pn was85%.The critical level of SRWC ,at which the plant needs irrigation,was40%.
出处
《果树学报》
CAS
CSCD
北大核心
2003年第2期116-119,共4页
Journal of Fruit Science
关键词
美国黑莓
土壤含水量
净光合速率
American black raspberry
Soil relative water content
Net photosynthetic rate
