土壤水分对烟苗生长及光合特性的影响

本文用两个烤烟品种为材料进行盆栽试验,研究了土壤水分对种子萌发、烟苗成活及生长的影响。结果表明,随着烟苗逐渐长大,对土壤水分含量的要求逐渐降低。种子萌发最适宜的土壤相对持水量为90%~95%,十字期烟苗成活最适宜的土壤相对持水量为70%~85%;生根期壮苗的特征是根系发达,地上部生长健壮,根/冠比值较大,烟苗含水量适中,最适土壤相对持水量为60%左右;成苗期壮苗的特征是茎秆短粗,叶面积大小适中,叶片较厚,比叶重较大,根系发达,根/冠比值大,叶绿素含量高,净光合速率强,最适土壤相对持水量为60%左右。为培育壮苗,应严格控制烟苗各时期的土壤相对持水量。 

Effect of soil moisture on the seedling growth and photosynthetic characters in tobacco

Two flue-cured tobacco varieties were selected and planted in pots to carry out experiment. Results showed that the required soil moisture content decreased gradually in seedling growth period, and the optimum soil moistare relative capacity was 90% ~ 95% for seed germination and 70% ~ 85% for seedling surviving. A healthy seedling in growth period should have a well developed root system and a healthy vigorous top, the ratio of root-top should be high, the water content in seedling plant should be suitable and 60% soil moisture relative capacity was optimum. A healthy seedling for transplanting should be that its stem is thick and short, leaf area is suitable, leaf is thick, root system develops well, root/top ratio is high, chlorophyll content and photosynthetic rate are high. Before transplanting, the optimum soil moisture relative capacity for seedling is 60%.