影响蝴蝶兰类原球茎耐脱水性的主要因素

Main Influence Factors on the Dehydration Tolerance of Phalaenopsis Protocorm-like Bodies

摘要:

为探讨蝴蝶兰(Phalaenopsis spp.)类原球茎(protocorm-like body, PLB)耐脱水性的主要影响因素,对PLB的平均粒重、含水率、脱水相对湿度、时间、温度、光周期与耐脱水性的关系进行了研究。结果表明,PLB的平均粒重与脱水后失水率、含水率、相对电导率、成活率呈显著或极显著相关。在较高湿度下脱水,PLB的平均粒重越大,其脱水后的相对电导率下降幅度和成活率提高幅度也越大。脱水PLB的失水率或含水率与脱水湿度呈显著回归,与脱水时间都不显著回归。含水率较高的PLB脱水后的成活率明显提高,但在较高湿度下脱水,成活率提高幅度较小。52%的湿度下脱水2 d的PLB达到质膜损伤或干燥致死的临界值。当PLB脱水至相近含水率,慢速脱水的PLB有较低的相对电导率和较高的成活率;在较低温度或暗中脱水可使PLB成活率提高。因此,蝴蝶兰PLB的耐脱水性与其自身重量、含水率有关,脱水湿度、时间、温度以及光照是影响耐脱水性的主要外部因素。

Abstract:

The influence factors on the dehydration tolerance of Phalaenopsis PLB (protocorm-like body) were studied, including average grain weight and water content of PLB, as well as relative humidity, time, temperature, light period, et al. The results showed that average grain weight of PLB had very significant or significant correlations with water loss rate, water content, relative conductivity and survival after dehydration, respectively. When PLB were dehydrated at high humidity, the bigger average grain weight of PLB, the greater relative conductivity reduced and the survival increased. Both water loss rate and water content of dehydrated PLB had obvious regression relations with dehydration humidity, but not significantly regression relations with dehydration time. The survival of PLB with high water content increased obviously after dehydration, but the percentage of increasing was smaller at high dehydration humidity than that at low dehydration humidity. Under dehydrated at 52% RH for 2 days, plasma membrane damage and mortality of PLB reached critical values. Although the water contents of dehydrated PLB were close, the PLB dehydrated at slow speed had lower relative conductivity and higher survival than those dehydrated at rapid speed. Survival of PLB was high when dehydrated at low temperature or in the dark. Therefore, the dehydration tolerance of Phalaenopsis PLB was extremely sensitive to its weight and water content. Besides of the dehydration relative humidity and time, the dehydration temperature and light period were the main exterior factors that influenced on the dehydration tolerance of PLB.