外源激素处理对美洲南瓜植株生长的影响

为探究激素对南瓜植株生长的影响,试验采用不同浓度GA3、IAA、6-BA和BR处理短蔓美洲南瓜自交系X10和长蔓美洲南瓜自交系JIN234幼苗。结果表明,外源喷施GA3显著增加南瓜植株主蔓和第一节间长度,50 mg·L-1GA3使短蔓X10主蔓长度与长蔓JIN234达相同水平,外源喷施IAA、6-BA和BR均未增加南瓜植株主蔓长度,推测短蔓自交系X10属于GA激素敏感型。外源喷施IAA显著增加南瓜植株下胚轴粗度,对植株叶片和叶柄生长无影响;外源喷施6-BA抑制南瓜植株下胚轴伸长,低浓度(1 mg·L~(-1))6-BA增加叶片长度,降低叶片宽度,而高浓度(30 mg·L-1)6-BA抑制叶柄伸长;外源喷施BR对南瓜植株生长影响较小。内源激素检测发现X10体内有生物活性的GA3和GA4含量显著低于JIN234,无活性的GA34含量显著高于JIN234,推测自交系X10矮化与植物体内GA活性相关。

Effect of exogenous hormone treatment on the growth of pumpkin(Cucurbita pepo L.)

In order to investigate the effects of hormones to the growth of pumpkin, the seedlings of inbred line in Cucurbita pepo L., dwarf X10 and vine JIN234 were treated with different concentrations of GA3, IAA, 6-BA and BR. The results showed that exogenous GA3 could apparently increase the vine length and the first internode. The vine length of X10 could reach to the vine JIN234 at50 mg · L~(-1) of GA3. Exogenous IAA, 6-BA and BR couldn't promote the growth of the vine. It was concluded that the dwarf plant X10 belonged to the GA hormone deficiency type. Exogenous IAA could significantly increase the thickness of hypocotyls, and had no obvious effect on the growth of plant leaves and petioles; Exogenous 6-BA significantly inhibited hypocotyl elongation of plants. The low concentration(1 mg· L~(-1)) of 6-BA significantly inhibited the increase of leaf length and the decrease of leaf width, while the high concentration(30 mg· L~(-1)) of 6-BA significantly inhibited petiole elongation.Exogenous BR had little effect on plant growth. The content of bioactive GA3 and GA4 from X10 was significant lower than that from JIN234, the content of inactive GA34 from X10 was significant higher than that from JIN234 by analysing the contents of endogenous hormone, it was speculated that the dwarf phenotype of line X10 was related to the bioactive GA content in plants.