遮光处理对两种观赏栀子开花特性及挥发物的影响

为了探索遮光处理对栀子开花特性及挥发性成分的影响规律，为观赏栀子的科学配植及挥发物的调控提供理论依据。该研究以大花栀子(Gardenia jasminoides var. grandiflora)和小叶栀子(Gardenia jasminoides var．radicans)为试材，经过5个不同遮光CK₁(全光照对照，无遮阳)、CK₂(疏林遮阳，杜仲树下，遮光率为80%)、T₁(1层1针遮阳网，遮光率为60%)、T₂(1层2针遮阳网，遮光率为70%)和T₃(2层2针遮阳网，遮光率为90%)处理后，观测其开花特性(花期、开花时长、花量、开放率和花形态特征)，并采集鲜花，利用SPME GC MS(固相微萃取 气相色谱/质谱联用)技术，对两种栀子花的挥发性成分及相对含量进行测定。结果表明：(1)适当的遮光可以使两种栀子花花期提前，但对开花时长没有明显影响，重度的遮光会使两种栀子花花期延迟，开花时长缩短；两种栀子花的CK₁处理的花苞数和正常花数在5个处理中均最高，但CK₁与T₁的开放率没有明显差异，且均高于其他处理。(2)两种栀子花的花径/蕾长都随着遮光率的增加而减少，且花的开合程度随着遮光程度的增加而降低。(3)大花栀子共测出了4大类26种化合物，主要化合物有α 法呢烯、3 蒈烯、(E) Hex 3 enyl (E) 2 methylbut 2 enoate和乙酸芳樟酯；小叶栀子共测出4大类23种物质，主要化合物有3 蒈烯、惕各酸叶醇酯、苯酸甲酯和(3E，7E) 4，8，12 Trimeth yltrideca 1，3，7，11 tetraene。(4)两种栀子均在CK₁处理下的香气成分种类最多，并随着遮光率的增加而减少，但其中萜烯类物质的相对含量随着遮光率的增加先增加后减少，酯类物质的相对含量随着遮光率的增加先减少后增加。研究认为，遮光对这两个不同品种的栀子植物的开花特性有一定的影响，且在他们挥发物成分和相对含量上的影响更为显著。在实际园林植物配置中，建议将观赏栀子种植在适度遮光的环境下，如落叶疏叶的乔木下，尽量避免种植在强光和重度遮光的环境中。

Effect of Different Shading Treatments on Flowering Characteristic and Volatile Components of Two Gardenia jasminoides

To explore the influence of shading treatment on the flowering characteristics and volatile composition of Gardenia jasminoides, and to provide reference for scientific planting, maintenance and volatile composition regulation of ornamental gardenia, this study used two kinds of Gardenia jasminoides var. grandiflora and Gardenia jasminoides var. radicans as test materials, with five different shading treatments CK₁ (total illumination contrast, no shading), CK₂ (under the shade of Eucommia ulmoides, the shading rate was 80%), T₁ (one needle and one layer of shade net, the shading rate was 60%), T₂ (two needles and layer of shade the shading rate was 70%), and T₃ (two needles and two layers of shade, the shading rate was 90%). We researched and measured their flowering characteristics (flowering time, flowering duration, number of flowers, opening rate and morphological characteristics of flowers). We collected flowers, determined volatile composition and relative contents of two kinds of gardenia by using SPME GC MS. The results showed that: (1) proper shading advanced the flowering time of the two gardenias, and had no obvious effect on the flowering duration. Severe shading delayed the flowering time of the two gardenia and shorten flowering duration. The bud number and normal flower number of CK₁ treatment were the highest in 5 treatments, and the open rate of CK₁ and T₁ were not significantly different, and higher than that of other treatments. (2) With the increase of shading degree, the number of buds, the number of normal flowers and the opening rate were gradually reduced, and the flower diameter/bud length decreased with the increase of shading rate; (3) There were 26 compounds in 4 major groups, including alpha. Farnesene, 3 Carene, (E) hex 3 enyl (E) 2 methylbut 2 enoate and Linalyl acetate in G. jasminoides var. grandiflora. A total of 23 compounds were detected in G. jasminoides var. radicans, and the main compounds were 3 Carene, cis 3 Hexenyl tiglate, Benzoic acid, methyl esterand (3E, 7E) 4, 8, 12 trimeth yltrideca 1, 3, 7, 11 tetraene. (4) CK₁ treatment of the to gardenia showed the most variety of volatile components and decreased with the increase of shading rate, among which terpene substances increased first and then decreased with the increase of shading rate, and esters decreased first and then increased with the increase of shading rate. Shading treatment had great influence on the flowering characteristics and volatile composition of G. jasminoides var. grandiflora and G. jasminoides var. radicans. There was no significant difference in the effect of shading on the flowering characteristics of the two different species of gardenia, but there were significant differences in the composition and relative contents of volatile. In the arrangement of garden plants, it is suggested that ornamental gardenia should be planted in moderate shading environment, such as deciduous trees, and avoid planting in heavy light and heavy shading environment as far as possible.