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991.
乙烯和葡萄糖处理对‘洛阳红’牡丹切花花色和花青素苷合成的影响 总被引:1,自引:0,他引:1
以‘洛阳红’牡丹(Paeonia suffruticosa‘Luoyanghong’)切花为试材,研究10 μL ? L-1乙烯处理、1 μL ? L-1乙烯抑制剂1-MCP处理、90 g ? L-1葡萄糖处理、90 g ? L-1葡萄糖 + 10 μL ? L-1乙烯复合处理对切花花色和花青素苷含量的影响,以蒸馏水处理为对照。研究结果表明:乙烯处理的切花花色明度增加,红度和彩度下降,花瓣花青素苷含量下降;1-MCP处理与对照无显著差异;葡萄糖处理花色明度下降,红度和彩度增加,花瓣花青素苷含量增加;葡萄糖乙烯复合处理对切花花色及花青素苷积累也有明显改善与促进作用。对花青素苷合成相关基因表达量分析的结果表明,乙烯处理对基因表达有抑制作用,而葡萄糖处理有显著的正调控作用,葡萄糖乙烯复合处理则显著缓解了单独乙烯处理对基因表达的负调控作用。葡萄糖信号和乙烯信号之间一定程度上存在互作,葡萄糖缓解了乙烯对牡丹切花花青素苷合成的抑制作用。 相似文献
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从华北型黄瓜‘9930’中克隆了黄瓜苦味形成的关键基因Bi的启动子序列,通过酵母单杂交技术对黄瓜叶片cDNA文库进行筛选,寻找可以调控Bi表达的转录因子。通过对筛选结果的测序及比对,发现有7种转录因子重复出现,包括2个AP2/ERF家族、3个bZIP家族、1个WRKY家族转录因子和1个E3泛素类COP1蛋白。其中AP2/ERF家族转录因子CsERF(登录号:Csa7M448110)重复出现6次,出现概率高于其他转录因子。利用烟草瞬时表达系统,CsERF对Bi启动子的结合及激活作用得到了进一步验证。初步证明CsERF可以结合到Bi的启动子并激活其转录,推测其很可能就是黄瓜叶片中调控苦味形成的关键转录因子。 相似文献
996.
The influence of co‐infection on concentration and accumulation of genetically different isolates of Potato virus Y (PVY) in potato and tobacco plants and the efficiency of transmission by Myzus persicae of PVY isolates from doubly versus singly infected plants were evaluated. The vector ability to simultaneously transmit two virus isolates was examined. Eight PVY isolates represented three strain groups: PVYO (pathotype and serotype O), PVYNW (pathotype N and serotype O), and PVYNTN (pathotype and serotype N). Different diagnostic methods, including DAS‐ELISA, multiplex RT‐PCR, aphid transmission tests and bioassays, were applied to detect the presence of PVY isolates in source and assay plants. Significant reductions in concentrations of certain PVY isolates during co‐infection with other isolates were found both in potato and tobacco plants. The observed effects were both isolate‐ and host‐dependent in form. The highest rates of virus transmission by single aphids were recorded with PVYNTN isolates, and the lowest ones with PVYO isolates. Individual aphids of M. persicae were able to simultaneously transmit two PVY isolates. The frequency of transmission was generally low, but it reached as high as 20% for one of the isolate combinations. The findings presented in the work provide proof for antagonistic within‐plant interactions between isolates of PVY, with some implications of these interactions for virus transmission by aphid vectors. Consequently, this research contributes to a better understanding of the epidemiology of the disease caused by PVY. 相似文献
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998.
Shengxin Wu Bin Wang Shujun Zhang Zhijun Tong Yazhi Chen Shunhui Chen Yuanlin Duan Weiren Wu 《Plant Breeding》2014,133(5):672-677
Tobacco bacterial wilt (TBW) is one of the most serious tobacco diseases in the world. Studies have shown that tobacco resistance to TBW is quantitatively inherited. This study aimed to map quantitative trait loci (QTL) conferring TBW resistance. An F2 : 3 population containing 237 lines was developed from a cross between two flue‐cured tobacco cultivars, ‘Yanyan 97’ (YY97; moderately resistant to TBW) and ‘Honghua Dajinyuan’ (HD; highly susceptible to TBW), and a linkage map consisting of 201 simple sequence repeats (SSR) markers and spanning a total length of 2326.7 cM was constructed based on the population. Field experiments were conducted 2011 and 2012, and disease symptoms were investigated three times in each year. The phenotypic data were analysed either separately or jointly for QTL mapping using the software QTLNetwork 2.1. Eight QTL with significant main effects were mapped on chromosomes 2, 6, 12, 17 and 24. A major QTL (qBWR17a) was detected on chromosome 17, which explained up to 30% of the phenotypic variation. The results can facilitate marker‐assisted selection (MAS) in TBW resistance breeding programme. 相似文献
999.
高压处理对鲜切果蔬品质与微生物影响的研究进展 总被引:2,自引:0,他引:2
综述了高压处理对鲜切果蔬质量与安全影响的研究进展,涉及鲜切果蔬的感官品质与营养品质、抗氧化能力、与品质变化有关的酶、微生物及细胞结构等内容,并对鲜切果蔬高压处理的发展方向进行了展望。高压处理是一种采用50-1 000 MPa压力处理食品的非热加工技术。适宜的高压处理能够改善鲜切果蔬的口感,但过高的压力(>200 MPa)会对感官品质产生不良影响;高压下鲜切果蔬营养品质的变化与原料及处理条件有关,低压处理可以提高鲜切果蔬的抗氧化能力,压力过高则导致抗氧化能力下降;与鲜切果蔬品质有关的大多数酶在相对低的压力下受到的影响不大,甚至还有被激活的现象,但随着压力升高,如达到400 MPa以上,一些酶活性明显下降,而有些酶甚至需要600 MPa以上的压力才能失活;高压下微生物失活的程度取决于微生物类型、压力大小、处理温度与时间等,高压处理后鲜切果蔬上的微生物均有不同程度的失活,但如果采用的高压条件不能完全杀灭鲜切果蔬上的微生物,则会面临很大风险,即使在4℃下贮存,也不能阻止微生物增长。总的来看,相对低的压力处理(<300 MPa)不能完全灭活鲜切果蔬上的微生物,尽管这还取决于果蔬种类及初始微生物的种类与数量,但高压在鲜切果蔬产品安全控制上面临挑战,因为过高的压力会导致鲜切果蔬产品的品质不被接受,因而寻找联合而非单一高压处理技术可能是一种解决方案。超过100 MPa的压力会对果蔬细胞结构产生影响,高压下鲜切果蔬产品的品质及微生物数量变化与高压下细胞结构的改变有关。因此,选择适宜的耐高压的原料品种,采用更有效的联合高压技术及危害分析与关键点控制管理,是实现高压技术在鲜切果蔬加工生产应用的前提,也是保障鲜切果蔬高压产品品质与安全的有效措施。未来鲜切果蔬高压研究将面向数字化模拟高压对果蔬细胞结构的影响、高压下鲜切果蔬风味的控制、联合高压技术开发及适宜高压加工的鲜切果蔬原料品种的选择等。 相似文献
1000.
Cultivar differences in gaseous 1-methylcyclopropene accumulation in whole and fresh-cut apple fruit
A number of studies have shown that responses of apple fruit to 1-methylcyclopropene (1-MCP) vary considerably among cultivars. This study was designed to determine if cultivars show differences in accumulation of gaseous 1-MCP. Apple fruit were placed in 1.76 L jars that were sealed and injected with 20 μL L−1 1-MCP. After 12 h, samples of intercellular atmosphere were removed and analyzed for 1-MCP concentration. Accumulation of internal gaseous 1-MCP varied markedly among cultivars, ranging from 0.14 ± 0.06, 0.22 ± 0.03, and 0.77 ± 0.30 in ‘Redcort’, ‘McIntosh’, and ‘Empire’, respectively, to 2.10 ± 0.28, 3.33 ± 0.13, and 6.93 ± 0.35 μL L−1 in ‘Gala’, ‘Cameo’, and ‘Honeycrisp’, respectively. Accumulation of gaseous 1-MCP was reduced an average of 51% in fruit treated with Sta-Fresh 8711 fruit wax. The role of the epidermis in modulating 1-MCP ingress was determined by measuring gaseous 1-MCP accumulation in fresh-cut tissue. Fresh-cut cortical tissue rapidly depleted headspace 1-MCP (>95%) over a 1-h exposure yet accumulated negligible quantities of internal gaseous 1-MCP. By contrast, cortical tissue treated with ascorbic acid or hypotaurine, or aged for several hours prior to exposure to 1-MCP, showed reduced consumption of headspace 1-MCP and high accumulation of internal gaseous 1-MCP. Levels of internal 1-MCP in cortical tissue from the cultivars generally paralleled those for intact fruit, ranging from 0.23 ± 0.07, 0.37 ± 0.18 and 1.09 ± 0.14 μL L−1 in ‘Empire’, ‘McIntosh’ and ‘Redcort’, respectively, to 2.40 ± 0.71, 4.55 ± 0.15, and 6.24 ± 0.85 in Gala’, ‘Cameo’, and ‘Honeycrisp’, respectively. Although commercial fruit wax influences gaseous 1-MCP accumulation, the comparable accumulation patterns in unwaxed whole and fresh-cut apple fruit suggest that epidermal tissue/native waxes alone do not account for cultivar differences. 相似文献