利用突变体研究植物激素对番茄果实品质的影响

分别对番茄中植物激素茉莉酸(JA)、脱落酸(ABA)、乙烯(ETH)和赤霉素(GA)的生物合成缺失型突变体植株进行果实农艺性状的分析,探索了这4种内源植物激素在番茄果实发育的典型时期对其品质的影响,结果表明：在番茄果实发育的不同时期,不同植物激素对果实品质的影响各不相同。如在外观品质方面,JA和ETH显著影响红熟期果实硬度,ABA和GA显著影响果实果形指数以及果实大小;在营养品质方面,在番茄果实发育的几个典型时期,其营养成分类胡萝卜素、蛋白质、可溶性固形物和还原糖等均受到JA、ABA、ETH和GA的共同调节,说明番茄果实发育过程中,其外观品质和营养品质均不同程度的受到JA、ABA、ETH和GA等内源植物激素的精细调控。     

脱落酸对番茄部分果实性状和营养品质的影响

为研究脱落酸(ABA)对番茄果实品质的影响,本研究测定了番茄ABA生物合成缺失突变体not和flc及其野生型各成熟时期果实,以及外源100 μmol·L^-1 ABA处理后不同天数的番茄果实的外观品质和营养品质。结果表明,内源ABA缺失抑制番茄果实增重并促进果实纵向生长,但对果实硬度无明显影响。同时,内源ABA可影响番茄果实可溶性固形物含量并促进破色期和转色期的还原糖积累。not和flc果实中番茄红素、β-胡萝卜素、叶黄素和总类胡萝卜素含量均显著高于其野生型,且外源喷施试验表明,与对照组相比,外源100 μmol·L^-1 ABA处理能显著抑制番茄果实中番茄红素、β-胡萝卜素和总类胡萝卜素的积累。综上,ABA在调控番茄果实外观品质方面,可促进番茄果实增重并抑制番茄果实纵向生长;在调控番茄果实营养品质方面,可促进还原糖积累并抑制类胡萝卜素积累。本研究结果为利用ABA调控番茄果实品质提供了一定的理论依据和技术支持。     

静电场处理对贮藏番茄品质及生理变化的影响

为探讨静电场对番茄贮藏品质的影响,以“朝研219”绿熟番茄为试材,从控制软化和转红出发,筛选了适宜的静电场处理条件为：场强-200 kV/m,频度2 h/d。研究静电场处理对贮藏番茄品质和生理变化的影响,结果表明：静电场处理能显著延缓番茄果实硬度的下降,抑制由绿转红的过程;可以延缓果实可溶性糖含量的下降和可滴定酸含量的上升;经负高压静电场处理的番茄,呼吸跃变推迟6 d出现,乙烯峰的出现也延迟了3 d,相对电导率与丙二醛含量较对照明显降低,说明静电场处理可调控果实细胞膜透性的变化。     

不同处理对海沃德猕猴桃内源ABA相关代谢基因表达的影响

为在分子水平阐明外源乙烯利、1-MCP和ABA处理对海沃德猕猴桃内源ABA合成代谢的影响,并揭示ABA调控果实后熟机理。本研究以海沃德猕猴桃果实为试验材料,利用外源乙烯利、1-MCP和ABA处理猕猴桃果实,分别运用高相液相色谱(HPLC)和RT-qPCR分析20℃贮存条件下对猕猴桃内源ABA合成、信号通路相关基因XanDH、PYR/PYL、PP2C、ABF的表达量影响。结果表明,乙烯利处理下PP2C和ABF基因表达量在DAH17~DAH58都显著低于对照组,XanDH和PYR/PYL在DAH17均显著高于对照组,而后迅速回落。在ABA处理下XanDH基因表达量呈先下降后上升再下降的趋势,在DAH17表达量最高。PP2C和PYR/PYL在DAH17经历高峰后逐渐回落至低水平,与对照组差异显著。ABF在采后前期有较高的表达量,经历峰值后急速回落,在后熟中后期表达水平较低。1-MCP处理下,在整个后熟阶段,XanDH的表达量均显著高于对照组,在DAH17达到最大值,随后逐渐降落。与对照组相比,PP2C基因表达量持续上升,ABF基因持续下调;PYR/PYL在DAH17表达量最高而后下调,但仍显著高于对照组。表明乙烯利、1-MCP、ABA处理对海沃德猕猴桃内源ABA合成、信号传导有较大影响,本试验结果为进一步探究外源乙烯利、1-MCP和ABA对猕猴桃果实采后衰老的调控作用及机理提供了一定的理论依据。     

面向机器人采摘的番茄力学特性试验

番茄果实及果梗的力学特性,是采摘机器人设计与控制的重要依据。对不同成熟期的番茄果实进行了纵向和横向挤压试验,对其果梗进行了折断和拉断试验。试验表明番茄果实的抗挤压能力具有明显的各向异性,且从青果期至绿熟期达到最大,而后随着成熟度增加而迅速减小。利用简化结构对这一规律的力学原理进行了分析。果梗拉断和折断试验发现,果梗均从离层处断裂,与拉断相比,折断方式更省力和易于实现机器人采摘。     

甘蔗生长前期喷施乙烯利对叶光合器官形态结构的影响

在分蘖期用１００ｍｇＬ－１和４００ｍｇＬ－１浓度乙烯利对早熟、中迟熟两个熟性不同的甘蔗品种进行叶面喷施，喷后２～１０周内对新出叶的观测表明：①乙烯利对叶的长、宽有一定的抑制作用，１００ｍｇＬ－１浓度处理的抑制较轻。②对叶片维管束、叶肉细胞的发育分化起着深刻的影响，１００ｍｇＬ－１浓度处理对维管束和叶肉细胞的生长有所抑制，但却促进了其形态分化     

热处理条件对番茄采后冷害的影响

研究了绿熟番茄采后在３３℃和３８℃加热２，５，８ｄ及２±１℃下冷藏后的果实品质、冷害程度和生理变化。结果表明，适宜的热处理可降低果实呼吸强度、细胞膜电解质渗出率和丙二醛含量，增加游离脯氨酸含量，减轻果实冷害，且对果实硬度和可溶性固形物含量无显著影响。其中以处理温度时间组合３３℃、５ｄ和３８℃、２ｄ的效果最好；３３℃、２ｄ的处理温度较低、时间较短，因而效果不明显；８ｄ的处理时间过长，使细胞受到伤害，丙二醛含量和细胞膜电解质渗出率增加，果实明显变软，出现异味。番茄果实的冷害指数（ＣＩＩ）与细胞膜电解质渗出率呈正相关，相关系数ｒ＝０．９７４４。     

钙对赭曲霉毒素A(OTA)诱导拟南芥毒性的抑制作用

为丰富赭曲霉毒素A (ochratoxinA,OTA)的植物毒性及其作用机理,探究钙在OTA诱导的植物毒性调控作用机理,本研究采用添加外源Ca2+,钙离子螯合剂乙二醇双(2-氨基乙基醚)四乙酸(ethylenebis(oxyethylenenitrilo) tetraacetic acid,EGTA)及OTA等处理离体拟南芥(Arabidopsis thaliana)叶片,通过形态学观察,叶片相对电导率、活性氧含量(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)含量的测定等研究钙对OTA诱导的拟南芥毒性的影响,结果表明,在一定浓度范围内(0～50 mmol/L),外源Ca2+单独处理,拟南芥叶片形态学无明显变化,EGTA与OTA分别处理均会引起拟南芥叶片失绿、坏死病斑的形成,而Ca2+与OTA共同处理,能显著抑制OTA诱导的拟南芥叶片失绿、坏死病斑的形成,EGTA加剧OTA的毒性作用;OTA处理使拟南芥叶片相对电导率升高,细胞膜通透性增大,外源钙能显著抑制OTA引起的拟南芥叶片相对电导率升高(P＜0.05),20 mmol/L Ca2+的抑制作用最强,抑制率为61.32％.此外,OTA处理使拟南芥叶片细胞ROS的爆发及MDA的积累,对拟南芥造成氧化损伤,钙能显著抑制OTA诱导的拟南芥ROS爆发(P＜0.05),减少MDA的生成,抑制率分别为29.7％和71.4％.研究结果说明OTA能诱导拟南芥的植物毒性,钙能显著抑制OTA诱导的拟南芥植物毒性,钙在拟南芥受外界胁迫中起重要作用.     

浸钙对黑宝石李果实采后品质和延缓衰老的影响

采用不同浓度CaCl₂溶液浸泡黑宝石李采后果实，研究对其果实品质和延缓衰老的影响，达到延长贮藏期的目的。 结果表明：浸钙处理可显著抑制采后贮藏过程中果实可滴定酸含量、硬度和可溶性糖含量的下降，浸钙处理降低了果实可溶性固性物含量；贮藏期间浸钙处理后乙烯释放量显著低于对照，且峰值出现的时间比对照推迟15 d；浸钙处理可保持采后贮藏过程中果实较高的超氧化物歧化酶(SOD)活性和较低的丙二醛(MDA)含量，维持细胞内活性氧代谢平衡，显著降低膜脂过氧化作用，从而延缓果实成熟衰老进程，较好的保持了果实品质。4种钙浓度处理中以1％和2％CaCl₂溶液浸果效果较好。     

外源5-氨基乙酰丙酸对番茄成熟过程中果实品质和矿质元素含量的影响

5-氨基乙酰丙酸(ALA)为高等植物中叶绿素等卟啉类化合物的生物合成前体,在促进作物生长、增强抗逆性及提高产量方面发挥着重要作用。为探究ALA对番茄果实成熟过程中品质和矿质元素含量的影响,本研究以原味1号品种为试验材料,向绿熟期番茄果实表面涂抹不同浓度(0、50、100、200、300 mg·L^-1)ALA溶液,筛选出促进设施栽培番茄成熟及品质形成的最佳ALA施用浓度,并进一步研究其对设施番茄果实成熟过程中硬度、可溶性固形物以及矿质元素含量的影响。结果表明,外源ALA通过降低果实硬度促进了果实的成熟,并通过提高番茄果实中可溶性固形物含量提升了果实品质。另外,在坐果后40 d,200 mg·L^-1ALA处理的K、Ca和Fe元素含量分别比对照提高了21.82%、56.25%和12.86%,但P、Mg和Cu元素含量分别比对照降低了9.92%、21.74%和25.00%。相关性分析结果表明,可溶性固形物含量与K含量呈正相关关系,与Cu含量呈负相关关系;果实硬度与K含量呈负相关关系。成熟期番茄果实中P含量与Cu含量呈正相关,与Mn、K和Ca含量呈负相关...     

Preharvest L-arginine treatment induced postharvest disease resistance to Botrysis cinerea in tomato fruits

L-arginine is the precursor of nitric oxide (NO). In order to examine the influence of L-arginine on tomato fruit resistance, preharvest green mature tomato fruits (Solanum lycopersicum cv. No. 4 Zhongshu) were treated with 0.5, 1, and 5 mM L-arginine. The reduced lesion size (in diameter) on fruit caused by Botrytis cinerea, as well as activities of phenylalanine ammonia-lyase (PAL), Chitinase (CHI), β-1,3-glucanase (GLU), and polyphenoloxidase (PPO), was compared between L-arginine treated fruits and untreated fruits. We found that induced resistance increased and reached the highest level at 3-6 days after treatment. Endogenous NO concentrations were positively correlated with PAL, PPO, CHI, and GLU activities after treatment with Pearson coefficients of 0.71, 0.94, 0.97, and 0.87, respectively. These results indicate that arginine induces disease resistance via its effects on NO biosynthesis and defensive enzyme activity.     

Abscisic acid improves tomato fruit quality by increasing soluble sugar concentrations

Abscisic acid (ABA) is crucial in fruit maturation and senescence and is considered as the other ripening control factor other than ethylene. Important components in ripening fruit are soluble sugars, which make the fruit sweeter and carotenoids, important flavor compounds in ripened fruit. The purpose of this study was to examine the effects of foliar ABA and calcium (Ca) fertilizer treatments (individually and in combination) on determinate beef-steak greenhouse tomato (Solanum lycopersicum) leaf chlorophylls and carotenoids, fruit carotenoids, and soluble sugar concentrations. Foliar spray treatment of 500 mg L^?1 ABA increased zeaxanthin (ZEA) and β-carotene (BC) in tomato leaf tissue. Increases in Ca fertilizer treatments significantly decreased tomato leaf violaxanthin (VIO), but no effect on other carotenoids. The application of 500 mg L^?1 ABA foliar spray significantly increased glucose and fructose concentrations in tomato fruit tissue. Foliar application of ABA treatments can increase overall chlorophyll, carotenoid content, and fruit quality.     

乙烯受体基因LeETR1和LeETR4的克隆及在番茄果实中的表达

摘要：为研究野生型番茄（Lycopersicon esculentum Mill. cv . Lichun）和转反义ACS 番茄果实中乙烯受体基因LeETR1和LeETR4的表达与乙烯的关系，实验用RT-PCR方法扩增了乙烯受体基因LeETR1和LeETR4片段，用两片段作探针进行Northern 杂交。结果表明：两受体基因的表达在番茄果实成熟进程中变化不明显，LeETR4在同一时期的果实外果皮中表达水平低于其在辐射壁和中柱的表达。转反义ACS番茄果实中LeETR1和LeETR4的表达水平显著低于野生型番茄果实，外源乙烯处理转反义ACS番茄果实，促进两个受体基因的表达。可见果实中LeETR1和LeETR4的表达受乙烯调控的影响。     

贵州本土半野生番茄砧木介导ABA生物合成信号通路调控植株耐旱性的机理研究

随着全球气候变暖,干旱胁迫成为限制番茄等蔬菜作物安全生产的重要因素之一。前期研究发现嫁接贵州本土半野生番茄GZ-01砧木其可以提高植株的耐旱性。为探究野生番茄GZ-01增强植株耐旱性的分子机理,以半野生番茄GZ-01砧木和红果番茄为试验材料,结合形态生理学和分子生物学,比较嫁接番茄和自嫁接番茄植株对干旱胁迫的响应。结果表明,干旱胁迫下,与自嫁接植株R/R相比,GZ-01/R嫁接植株细胞膜的损伤显著降低,植株的抗氧化能力、干物质累积量、CO2同化率和水分利用率显著提高,离体叶片失水率显著降低,下气孔闭合比率显著提高,脱落酸（ABA）合成相关基因表达量和ABA含量显著提高。嫁接植株GZ-01/R可能通过调控ABA的合成来影响气孔开闭,调控叶片失水率,提高植株水分利用率,从而影响植株对干旱胁迫的响应。本研究为开发利用贵州本土半野生番茄资源奠定了基础,为增强干旱胁迫和分子调控网络途径提供了理论支撑。     

Involvement of negative feedback regulation in wound-induced ethylene synthesis in 'Saijo' persimmon

Wounding is one of the most effective stress signals to induce ethylene synthesis in persimmon (Diospyros kaki Thunb.). We found that wound-induced ethylene biosynthesis is subjected to negative feedback regulation in mature 'Saijo' persimmon fruit since ethylene production was enhanced by 1-methylcyclopropene (1-MCP) (an inhibitor of ethylene perception) pretreatment, which was approximately 1.8 fold of that in control tissues (without 1-MCP pretreatment). Wound-induced 1-aminocyclopropane-1-carboxylate (ACC) synthase activity and DK-ACS2 gene expression were substantially increased by 1-MCP pretreatment after 12 h, which resulted in much higher ACC content in 1-MCP pretreated tissues than that in a control after 24 h. These results indicated that wound-induced DK-ACS2 gene expression was negatively regulated by ethylene in mature persimmon fruit. However, 1-MCP pretreatment had no effect on DK-ACO1 gene expression, suggesting the independence of wound-induced DK-ACO1 on ethylene. Out of accord with DK-ACO1 gene expression, ACC oxidase activity was enhanced 48 h after wounding in 1-MCP pretreated tissues, reaching a peak 1.5-fold higher than that in control tissues at 60 h.     

超表达亚硫酸氧化酶基因对促进番茄果实亚硫酸盐氧化的研究

本研究以亚硫酸氧化酶基因（SO）超表达系（OE）、干扰系（Ri）及野生型（WT）的绿熟番茄果实为材料,经SO2熏蒸后,12℃低温贮藏,研究亚硫酸氧化酶基因的超表达,对番茄贮藏期间相对电导率、亚硫酸盐含量、番茄红素含量及成熟度的变化。结果表明,经SO2熏蒸后,Ri果实较WT果实表现为相对电导率增加,亚硫酸盐残留较多,番茄...     

Relationships between respiration, ethylene, and aroma production in ripening banana

Mature green bananas were treated with the ethylene antagonist 1-methylcyclopropene (1-MCP) at intervals during the 24 h period after initiation of ripening with propylene. Following 1-MCP treatment, the fruits were ripened in either air or propylene while ethylene, carbon dioxide, and volatile production and composition were monitored at regular intervals. The application of 1-MCP significantly delayed and suppressed the onset and magnitude of fruit respiration and volatile production. The 1-MCP treatments also caused a quantitative change in the composition of the aroma volatiles, resulting in a substantial increase in the concentration of alcohols and a decrease in their related esters. The results showed that ethylene has a continuing role in integrating many of the biochemical processes that take place during the ripening of bananas.     

不同施钙措施对番茄果实钙含量和钙形态的影响

在营养液中加钙及在花期、幼果期分别向花、叶、幼果喷施20mg.L萘乙酸(NAA)+0.5%CaCl2混合液能够显著增加果实钙含量,其中营养液高钙和喷叶处理增钙效果最好,喷幼果和喷花处理也有较明显的效果,3周大果喷钙对果实增钙效果不明显。增钙的同时,不同措施不同程度影响了果实K、Mg、P及某些微量元素的含量。果实增钙主要是增加了果胶酸钙含量,以营养液高钙、喷叶和喷幼果处理增加程度最高;各种施钙措施显著增加了果实Vc含量,降低了可滴定酸度,改善了果实品质。还探讨了不同施钙措施对植株各部位钙含量和果实钙含量的影响机理。     

Salinity and mineral nutrition effects on growth and accumulation of organic and Inorganic ions in two cultivated tomato varieties

A trial was conducted on the effect of salinity and method of fertilizer application on two varieties of cultivated tomato, i.e. VF 145 and Edkawi. Salinity ranged from 0.52 to 11 dS/m, and fertilizer was applied by either broadcasting in small doses or added with irrigation water. Weight of shoots, fruit yield, and sodium (Na), calcium (Ca), chloride (Cl), free proline contents in both developing and mature leaves, and total soluble salts and ascorbic acid contents in fruits were taken as evaluating criteria. Salinity depressed both growth and fruit yield, and simultaneously increased ion concentration in plant leaves. Sodium and Cl accumulated with salinity, being greater in mature leaves, while proline accumulation in developing leaves was much higher than in mature leaves. Total soluble salts and ascorbic acid were not affected. Liquid fertilization resulted in higher fruit yields than that obtained with the solid fertilizer treatments as well as better alleviating the depressive effects of salinity on plant growth and yield, especially at the lower salinity level where it was more beneficial to fruit yield. The VF 145 tomato variety was found a bit more sensitive to salinity than the Edkawi variety, and was affected differently by salinity, regarding both the yield and the pattern of organic and inorganic ion accumulation. Our results suggest that there exists a physiological mechanism that is involved in the salt tolerance difference observed between the two varieties that needs to be investigated.