Page 153 - 《广西植物》2024年第7期
P. 153
7 期 彭欢等: 罗汉果品质受气候因子影响及其分子调控机制 1 3 5 3
Abstract: In order to investigate the impact of climatic factors on the quality of Siraitia grosvenorii fruits pollinated in
different seasons and the underlying molecular mechanism involvedꎬ the differences in climate factorsꎬ quality traitsꎬ and
gene expression between fruits of the main cultivar S. grosvenorii “Qingpiguo” pollinated in summer and autumn were
statistically analyzed by monitoring climate factors at different developmental stagesꎬ measuring morphological changesꎬ
detecting mogroside metabolismꎬ and analyzing gene expression using qRT ̄PCR. The results were as follows: (1)
Compared to summer ̄pollinated fruitsꎬ the average temperature and effective accumulated temperature of autumn ̄
pollinated fruits decreased significantly after 35 d. Additionallyꎬ the temperature difference between day and night
increased significantly before 65 d. Howeverꎬ this difference was still less than that of the average temperature and
effective accumulated temperature. The light intensity and air humidity remained similar. (2) The transverse diametersꎬ
longitudinal diametersꎬ and single fruit weights of autumn ̄pollinated fruits increased compared to those of summer ̄
pollinated fruitsꎬ howeverꎬ these differences were not statistically significant. (3) Mogroside V and 11 ̄O ̄mogroside V in
autumn ̄pollinated fruits accumulated slowly from 55 d with a delay of about 10 dꎬ moreoverꎬ the content of both
compounds in ripe fruits decreased by 40.66% and 46.07%ꎬ respectively. (4) In autumnꎬ the number and extent of up ̄
regulated mogroside V synthetase genes were relatively lowerꎬ and their co ̄expression consistency was poorer than in
summer. Furthermoreꎬ the glucosyltransferase gene SgUGT94 ̄289 ̄3 which was responsible for the final step in mogroside
V biosynthesisꎬ exhibited down ̄regulation at all time points of 55 d. In summaryꎬ the shape and size of S. grosvenorii
fruits pollinated in different seasons were not significantly affected by climatic factorsꎻ howeverꎬ the content of mogroside
V was significantly influenced by the temperatureꎬ which potentially influences these variations in mogroside V by
regulating both the co ̄expression consistency and expression level of mogroside V synthetase genes. The results of this
study provide the theoretical reference for high ̄quality cultivation and genetic breeding of S. grosvenorii.
Key words: different seasonsꎬ Siraitia grosvenorii qualityꎬ climatic factorsꎬ fruit sizeꎬ mogroside V contentꎬ
gene expression
罗 汉 果 ( Siraitia grosvenorii ) 是 葫 芦 科 批成熟ꎮ 不同产区和生长季气候因子变化会直接
(Cucurbitaceae) 罗 汉 果 属 ( Siraitia) 药 用、 甜 料 植 影响果实成熟和内外品质ꎮ 咖啡高温时果实成熟
物ꎬ其干燥果实为知名传统中药材ꎬ具有清热止 早而品质差(Aparecido et al.ꎬ 2018)ꎮ 葡萄高温时
咳、抗炎平喘、祛痰润肺、润肠通便、降糖降脂、抗 成熟度和酸度高ꎬ低温时主要活性成分维生素 C、
氧化、抗癌、抗纤维化等功效( 唐昀彤等ꎬ2021ꎻ戴 多酚和花青素含量高( Rafique et al.ꎬ 2023)ꎬ平均
胜和汪惠丽ꎬ2023)ꎬ富含三萜皂苷活性成分罗汉 温度和湿度高有利于糖分积累( 乔振羽等ꎬ2023)ꎮ
果苷Ⅴ等多种高强度甜味物质ꎬ其中罗汉果苷Ⅲ、 黑加仑高温时果实萜类挥发物质积累增加ꎬ低温
罗汉果苷Ⅵ、罗汉果赛门苷Ⅰ、罗汉果苷Ⅴ、11 ̄O ̄ 时果实的有机酸积累增加( Pott et al.ꎬ 2023)ꎮ 黄
罗汉果苷Ⅴ和异罗汉果苷Ⅴ的甜度分别为蔗糖的 瓜香气物质 C 醛类含量与平均光照强度呈正相
6
195、 300、 465、 378、 68 和 500 倍 ( Murata et al.ꎬ 关ꎬC 醛类含量与平均相对湿度呈负相关( Li et
9
2006ꎻ Jia & Yangꎬ 2009)ꎮ 罗汉果甜苷因其热量 al.ꎬ 2019)ꎮ 黑莓前期成熟果实比后期的单果重
低、安全无毒等特点ꎬ糖尿病、高血压、肥胖人群均 和有机酸含量高ꎬ但是花青素和可溶性固形物含
可食用ꎬ已被大规模提取用作甜味剂ꎮ 近年来ꎬ罗 量低( Mikulic ̄Petkovsek et al.ꎬ 2023)ꎮ 加工企业
汉果需求越来越大ꎬ效益也逐渐增加ꎬ该产业已成 认为罗汉果前期成熟果实因生境温度高而品质差
为乡村振兴的支柱产业ꎬ种植区域也由道地产区 会增加原料成本ꎬ后期成熟果实因生境温度低、昼
向周边地区快速蔓延ꎮ 但是ꎬ果实甜苷含量较低 夜温差大而品质高可降低原料成本ꎬ因而偏好采
导致甜味剂提取原料成本高ꎬ成为罗汉果产业的 购后期成熟果实ꎮ 由于高甜苷新品种选育周期
发展限制瓶颈ꎮ 这不仅与当前罗汉果栽培品种有 长ꎬ因此目前通过研究不同季节授粉果实品质具
关ꎬ还与果实成熟批次有一定的相关性ꎮ 罗汉果 体差异及其受生境气候因子影响情况指导罗汉果
种植需人工授粉才能结果ꎬ授粉期集中在 7 月初 适宜种植区域选择以及高产优质种植技术优化ꎬ
到 8 月底ꎬ7 月夏季和 8 月秋季授粉果实通常分两 减少成熟果实品质的差异ꎬ从而降低甜味剂提取