The potential of ripening mutants for extending the storage life of the tomato fruit

Summary The effect of the fruit ripening mutants rin, gr, nor and Nr on storage life and pigmentation was investigated in homozygous material, in heterozygous F₁ combinations between the mutants with the colour mutant hp and with the normal cv. Kewalo. Crosses with nor showed a 3-to 5-fold increase in storage life in comparison with the normal cv. or with hp. Maximum pigmentation of the fruits of crosses with nor was pale-red with vineripened fruit and pink with fruit harvested at the breaker stage and ripened on the shelf. The ripening inhibitory effect of rin in the different F₁ combinations was less pronounced than that of nor, and the colour of the fruits was improved. Fruits of the F₁ cross between rin and nor showed greatly improved storage life and developed pink or pale red colour. Most heterozygotes with hp showed improved pigmentation. Problems anticipated in utilizing ripening mutants in breeding for improved keeping quality are discussed.     

黄淮冬麦区晚霜冻易发时段冠层内最低气温分布及估算

利用2016年和2017年3月中旬?4月下旬两次典型低温过程中,冬小麦田间不同高度逐小时气象观测数据,分析晚霜冻易发时段冬小麦冠层内最低气温出现高度及其变化规律,构建基于150cm高度处气象因子和地表0cm温度的冠层内最低气温估算模型。结果表明：（1）与150cm高度相比,两次典型低温过程中0℃以下气温在冠层高度附近出现时间更早,持续时间更长且温度更低;（2）最低气温总是出现在4/5冠层高度附近,并在2：00?6：00时段,尤以5：00左右发生频率最高;（3）冠层内最低气温与150cm高度处相对湿度、风速的相关性通过了0.01水平的显著性检验,与不同高度气温、不同土壤深度地温的相关性也通过了0.001水平的显著性检验,与地温的相关性随着土壤深度的增加而逐渐降低;（4）冠层内最低气温与150cm高度处气温、风速、相对湿度,以及0cm地温的偏相关系数大小排序表现为,气温＞风速＞地温＞相对湿度;利用以上因子构建基于多元线性回归函数的冠层内最低气温估测模型,其估测值与实测值拟合结果的决定系数达到0.967,均方根误差为0.915。说明基于气象台站常规观测数据构建冠层内最低气温估测模型具备一定可行性,可为冬小麦晚霜冻害的监测预报提供数据支持。     

基于计算机视觉的番茄催熟与正常熟识别

国内常有菜农采摘远离成熟期的番茄,采用乙烯利处理进行催熟,为了阻止催熟番茄进入瓜果市场危害食用者的身体健康,给出了催熟番茄识别系统的硬件组成,通过计算机视觉装置获取番茄透射光颜色参数（R、G、B）,并将RGB值转换成HIS值,采用遗传算法训练的多层前馈神经网络实现催熟番茄的自动识别。试验结果表明,系统正确识别率为91.7%,为进一步进行番茄催熟与正常熟识别的研究提供参考。     

Patterns and heritability of carboxylic acids and soluble sugars in fruits of apricot (Prunus armeniaca L.)

The investigation of acid and sugar content in an array of apricot cultivars and progenies indicates the existence of marked variability. Citric acid varied from 0.17 to 1.20% and malic acid from 0.21 to 1.51% on fresh weight. Fructose varied from 0.27 to 1.60%, glucose from 0.90 to 3.13% and sucrose from 1.92 to 6.92%. The estimate of heritability was high for total and main sugars, reaching over 0.50%. Acids generally showed low coefficients, although those for citric (0.27) and malic (0.36) were good. With the exception of one progeny, all genotype/year comparisons were not significant, showing constant patterns for acid and sugars over the years regardless of the variability in absolute values. This means that the patterns of each genotype are under genetic control. The wide range of diversity in acid and sugar content in apricot germplasm and the independent heritability for most of these compounds make it possible to breed and select cultivars with improved flavour on the basis of superior phenotypes.     

油橄榄的早实丰产栽培技术

在调查、总结四川省油橄榄栽培历史、种植技术及其试验研究成果的基础上,从品种选择,种植地选择,整地、造林,栽植后的土、肥、水管理,整形、修剪,病虫害防治等方面系统地介绍了四川省发展油橄榄的早实丰产栽培技术。     

Mangrove Habitat Formation and Response to Holocene Sea-level Changes on Kosrae Island,Micronesia

Mangrove habitats on Kosrae are divided into three types, i.e., an estuary or delta type, a backmarsh or lagoon type and a coral reef or tidal-flat type. Most of the mangrove forests of Kosrae have been developed during the last 2000 years by accumulating mangrove peat with the gradual sea-level rise of 1 to 2 mm/yr except the landward part of the estuary or delta type. On the other hand, during the period of rapid sea-level rise of about 10 mm/yr between 4100 and 3700 yr B.P., the mangrove forests ceased peat accumulation and retreated landward. Until 3500 yr B.P., mangrove forests were distributed only in narrow bands in the inlets. Therefore, the critical rate of mangrove peat accretion with sea-level rise is estimated at more than 2 mm/yr and less than 10 mm/yr. If the anticipated sea-level rise exceeds this critical rate, all of the mangrove forests of Kosrae will retreat landward and reduce rapidly.     

收获时期及干燥方式对花生品质的影响

为探索不同收获期和后熟干燥方式对花生品质的影响,该研究以泰花5号花生为试验对象,采用在株晾干法、鲜摘晾干法、鲜摘催干法3种方法对3个时期收获的花生进行后熟干燥品质对比测试分析。结果表明,在同一收获期中,在株晾干法花生百果质量、百仁质量显著高于其他2种方法,该后熟干燥方法的增重作用随收获期提前而更明显(P0.05);但在相同后熟干燥方法中,提前2周收获的干燥荚果百果质量、百仁质量均显著低于前1周和原定收期收获的花生荚果(P0.05)。自然晾晒干燥期间,在株晾干花生果壳、果仁含水率均高于同期鲜摘晾干果壳、果仁含水率,两种晾干方式含水率差异在初期逐渐增加、随后逐渐减小直至达到相当的最终含水率。鲜摘晾干和鲜摘催干果仁粗蛋白、粗脂肪均未见显著差异(P0.05),而在株晾干果仁粗蛋白、粗脂肪含量分别增加了3%、2%左右;而收获期越早,果仁粗蛋白和粗脂肪含量越低。在果仁不饱和脂肪酸总相对含量上,鲜摘晾干、在株晾干果仁与新鲜果仁未见差异(P0.05),但机械催干果仁显著低于新鲜果仁(P0.05)。在果仁氨基酸组成方面,经3种不同后熟干燥方法后,8种主要氨基酸及氨基酸总含量均呈现在株晾干含量最高、鲜摘晾干其次、机械催干最低的差异(P0.05)。在株晾干花生果柄横断面显微结构观察表明,果柄在干燥初期仍保留对水分、养分等物质输导、贮藏的空间通道,为荚果的物质代谢和积累提供必要条件。该研究结果为花生生产实践提供参考。     

苹果果实成熟期间电特性的研究

为了了解果实成熟期间电特性的变化规律,该文以红富士苹果为对象,研究了测试信号的频率和电压对成熟期苹果电参数的影响,果实生长中电参数和生理生化参数的变化,并分析了电参数变化的原因。研究结果表明：频率对苹果电参数的影响规律与苹果成熟度无关,但电压对苹果电参数的影响规律与苹果成熟度有关。苹果成熟期间,其呼吸强度持续下降;果实成熟前期,相对介电常数和pH值逐渐下降,后期逐渐增大;而电阻率和可溶性固形物含量在前期逐渐增大,后期减小。这些参数的转折点皆出现在同一时间,说明电参数与苹果内部品质之间存在必然的联系,可以用电参数反映内部物质成分的变化。     

葡萄果实转色过程中线粒体呼吸代谢变化

为明确线粒体呼吸代谢与果实成熟期间颜色形成的关系,本试验探究了3种葡萄果实(夏黑、巨峰和金手指)成熟期间颜色、总花色苷含量、呼吸强度、内源乙烯产生和线粒体呼吸代谢的变化规律。结果表明,夏黑和巨峰葡萄果实的果皮颜色指数(CIRG)值和总花色苷含量随着果实成熟呈上升趋势,而金手指葡萄果实CIRG值在整个成熟期间变化不显著;葡萄果实成熟期间呼吸强度和内源乙烯均呈先上升后下降趋势,在花后63d达到峰值。同时,葡萄果实成熟期间,线粒体膜通透性转换孔(MPTP)逐渐增加,线粒体膜流动性(MMF)持续下降;线粒体琥珀酸脱氢酶(SDH)活性随着成熟进程逐渐下降,而细胞色素氧化酶(CCO)活性在花后63d开始上升。表明盛花63d之后是果实色泽快速形成阶段,可能为葡萄果实色泽形成的关键时期。线粒体呼吸代谢增强促进了果实成熟期间呼吸强度增加和内源乙烯释放,从而使夏黑和巨峰果实中花色苷大量积累,加快了金手指葡萄果实叶绿素的降解和类胡萝素的合成。本研究结果为调控南方葡萄果实着色提供了理论依据。     

春性小麦的晚霜冻及防治研究

晚霜冻在长江下游对春性品种小麦扬麦１５８、扬麦５号会造成冻害,暖冬年１０月２０日前播种的春性小麦会因受到冻害而减产。受冻后的扬麦１５８有良好的自我恢复能力,减产幅度比扬麦５号小。长江下游１０月下旬初播种的春性小麦高产稳产,冬春镇压能预防与减轻早播麦的晚霜冻害,冻害后补肥有利于提高恢复能力。