GA_(4+7)和6-BA复配剂对百合切花保鲜的影响研究

Gibberellin and Benzyladenine Improve Postharvest Quality of Cut Lilies

百合是世界四大切花之一,远距离冷藏运输后易出现叶片黄化等现象,严重影响切花品质,是百合鲜切花生产和采后流通亟待解决的关键问题。试验于2014年8月在华中农业大学园林系采后实验室进行。以东方百合‘西伯利亚’(Lilium Oriental Hybrid‘Siberia’)的切花为试材,取自昆明芊卉种苗有限公司基地,每支切花带有3个花蕾,按照商业标准采收,冷藏并空运至武汉。将花枝基部剪斜口,保留花枝长度60cm,叶片15枚,处理时开花级数为2级(花蕾开始转色,但还未充分膨胀和显色)。试验条件:温度20~23℃,相对空气湿度约70%,白炽灯光强度10μmol·m-2·s-1,每日光照12h。复配剂采用GA4+7和6-BA,设计了以25mg·L-1,50mg·L-1浓度的复配剂叶面喷施各一次和2.5mg·L-1,5mg·L-1浓度的复配剂花枝下部浸泡各30min,共4个处理,以清水瓶插为对照。从处理瓶插日起,每隔2d对叶片黄化率(叶面积的30%以上发生黄化视为黄化,黄化叶片数与总叶片数的比率即为黄化率)、脱落率、花期(第1朵花花蕾顶部开裂至第3朵花萎焉)等形态指标进行检测。采用LICOR6400光合仪对花枝中部叶片的光合指标进行测定(8:00am^18:00pm,每隔2h观测一次),包括净光合速率、气孔导度、胞间CO2浓度和蒸腾速率。每个处理组8支切花,每次测定3个重复,数据统计采用SPSS13进行ANOVA显著性分析。研究结果 :4种处理均能不同程度的延长切花瓶插寿命,其中叶面喷施25mg·L-1浓度复配剂的花期可达14d,比对照组延长2.8d。4种处理均能明显改善叶片的黄化和脱落现象,效果依次为喷施50mg·L-1>喷施25mg·L-1>浸泡5mg·L-1>浸泡2.5mg·L-1。在处理后瓶插第15d,对照组的叶片黄化率、脱落率已分别达到100%和63.36%,而喷施50mg·L-1处理组仅为0和22.58%。对切花进行光合指标测定表明,处理组能增加瓶插期间尤其是开花末期叶片的净光合速率、气孔导度、胞间CO2浓度和蒸腾速率;在处理后瓶插第13d,对照组的净光合速率已显著降低,而处理组变化均较为平缓。结果表明:GA4+7和6-BA复合剂能延缓叶绿素的降解,通过对切花百合叶片品质的保持促进更多光合产物向花朵运输从而延长花期。喷施处理优于浸泡处理,但是喷施50mg·L-1高浓度的复配剂会引发瓶插后期花瓣边缘褐化症状,因此,建议在生产中采用叶面喷施25mg·L-1复配剂来提高百合切花品质。

Lilyis one of the most important cut flowers in the world. Long-distance transportation can induce leave yellowing or browning which seriously affect cut flower quality. The combinated effect of benzyladenine and gibberellin on vase life of ‘Siberia＇ was evaluated in this experiment. Cut lilys with 3 flower buds per plant were sprayed with 0, 25mg·L-1, 50mg·L-1（each of BA and GA4＋7） once or pulsed in the solution of 2.5m·L1g, 5mg·L-1（each of BA and GA4＋7） for 30 min. The results demonstrated that all treatments could prolong vase life. The flowering time could be extended to 14 d by 25mg·L-1 spray treatment, which was 2.8d longer than the un-treated group. In addition, four treatments could obviously suppress leave yellowing and falling（the effect order was ：spray 50mg·L-1spray 25mg·L-1pulse 5mg·L-1pulse 2.5mg·L-1）. The chlorotic leave ratio reached 100% and 0% at 15 days after treatment in control and 50mg·L-1 spray treatment group, respectively. Further test showed that all treatments could significantly improve net photosynthetic rate, transpiration rate, stomatal conductivity and intercellular CO2 concentration, retard chlorophyll decreasing and promote leave quality,which facilitated more photosynthetic assimilates transporting to flowers. Spray treatment was superior to pulse treatment, however 50mg·L-1 spray treatment could induce browing of petals. Thus, we recommend using 25mg·L-1 spray treatment for preservation of cut lily in production.