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.     

Non-destructive monitoring of flesh softening in the black-skinned Japanese plums ‘Angeleno’ and ‘Autumn beaut’ on-tree and postharvest

There is a need to develop alternative harvest indexes for black skinned plums. The aim of this research was to analyze and compare the most commonly used indexes for deciding the harvest date for Japanese plum, and evaluate the effectiveness of new approaches for studying maturation. The ripening process was monitored on-tree and during postharvest in a non-destructive way, through the absorbance of chlorophyll (I_AD), the compression strength of the intact fruit, and the traditional parameters associated with ripening. Fruit were harvested at commercial ripeness and “tree-ripe”, and were stored for 10 d at 22 °C and 75-80% RH. The I_AD decreased during the last phase of development of the fruit on-tree, and it was related to the common indexes used for plums. ‘Angeleno’ showed a decrease of the I_AD 24% lower than that observed for ‘Autumn beaut’. The I_AD versus time showed the highest coefficients of determination when compared with the soluble solids concentration (SSC), flesh firmness, hue (H°) and chroma (C*) of the skin. The compression strength of the intact fruit was associated with flesh firmness, and to a lesser extent with the SSC for ‘Angeleno’, whereas for ‘Autumn beaut’ higher correlations for both the SSC and flesh firmness were observed. The C* of the skin on ‘Autumn beaut’ showed an erratic change during ripening; by contrast, for ‘Angeleno’, this index showed a clear trend. During postharvest it was observed that for ‘Angeleno’ fruit picked at commercial ripeness, the rate of change of the I_AD was practically the same as observed on-tree, while for ‘Autumn beaut’ the rates of change on-tree and at postharvest were 0.075 I_AD d⁻¹ and 0.024 I_AD d⁻¹, respectively. For the “tree-ripe” fruit, the rate of change was practically the same for both cultivars. Similar trends were observed for the compression strength.     

美味猕猴桃果实后熟过程中主要品质指标的变化

研究了不同贮藏温度下美味猕猴桃果实后熟过程中主要品质指标的变化。在 0℃条件下 ,果实内的Vc、可滴定酸、可溶性固形物和总糖含量变化很小 ,硬度随着贮藏期的延长缓慢下降 ;在 2 0℃条件下 ,短期内果实品质变化较大 ,硬度也下降迅速 ;低温 (0℃ )可显著延缓果实品质的变化。     

The Influence of Co-Suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Ⅰ on the Expression of Fruit Ripening-Related and Pathogenesis-Related Protein Genes

The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase Ⅰ on the expression of fruit ripening-related and pathogenesis-related protein genes, and on the biosynthesis of endogenous ethylene and storage ability of fruits. Specific fragments of several fruit ripening-related and pathogenesis-related protein genes from tomato （Lycopersicon esculentum） were cloned, such as the l-aminocyclopropane-1-carboxylic acid oxidase 1 gene （LeAC01）, 1- aminocyclopropane-l-carboxylic acid oxidase 3 gene （LeAC03）, EIN3-binding F-box 1 gene （LeEBF1）, pathogenesis-related protein 1 gene （LePR1）, pathogenesis-related protein 5 gene （LePR5）, and pathogenesis-related protein osmotin precursor gene （LeNP24） by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato Ailsa Craig （AC＋＋） and the LeAC01 co-suppression tomatoes （V1187 and T4B）, respectively. At the same time, ethylene production measurement and storage experiment of tomato fruits were carded out. The hybridization results indicated that the expression of fruit ripening-related genes such as LeACO3 and LeEBF1, and pathogenesis-related protein genes such as LePR1, LePR5, and LeNP24, were reduced sharply, and the ethylene production in the fruits, wounded leaves decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in the transgenic tomato was suppressed. In the co-suppression tomatoes, the expression of fruit ripening-related and pathogenesis-related protein genes were restrained at different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.     

灌浆成熟期温度对稻米品质及有关生理生化特性的影响

1987年在湖南农学院分早、中、晚三季研究灌浆成熟期温度对稻米品质及有关生理生化特性的影响,结果表明:a.茎、鞘、叶的总淀粉和粗蛋白质含量快速减少,籽粒总淀粉和蛋白质积累快,直链淀粉和蛋白质含量升高,淀粉酶和蛋白酶浓度提高,气温大于35℃时淀粉酶和蛋白酶的活性则更高,可溶性糖在灌浆成熟后期增加,温度在30～35℃范围内,Q酶活性最高,籽粒直链淀粉减少。b.灌浆成熟期温度提高,籽粒灌浆速率增大,时间缩短,谷粒物质致密度差,容重下降,垩白指数增大,胶稠度变硬,糊化温度上升。此外,还探讨了稻米品质形成的气候生态生理机制。     

早熟板栗新品种‘岱岳早丰’

 ‘岱岳早丰’是从泰山板栗实生后代群体中选育出的新品种。早熟,优质,丰产,耐瘠薄。坚果光亮整齐,中大粒,果肉细腻,糯性强。适宜在泰沂山区的山地、丘陵和胶东山地栽培。     

早熟梨新品种-早金酥的选育

早金酥是以早酥为母本,金水酥为父本杂交育出的梨早熟新品种.果实呈纺锤形,平均单果质量240 g,最大质量600 g;果面绿黄色,果皮薄,肉质脆,果汁多,风味酸甜,石细胞少,品质极上.可溶性固形物含量10.8%,总糖含量8343 g·kg-1,可滴定酸含量2.527 g·L-1,维生素C含量33.72 mg·kg-1,硬...     

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。