缙云山草珊瑚(Sarcandra glabra)天然居群结实特征的变异性研究

对缙云山草珊瑚8个天然居群结实特征的20项表型性状的变异性进行了研究,结果表明:各表型性状在居群内与居群间都存在很大的变异性,其中种实产量、果序数和果序分枝的变异程度较高,而果实和种子的特征指数变异程度较低,同类性状果实的变异程度要大于种子;平均变异系数最大的性状是四分枝果序百分比(1.477),最小的是种子长宽比(0.041);变异程度最大的居群是居群6(0.564),最小的是居群4(0.292);各居群间除果序分枝总数差异不显著、果序数和二分枝果序百分比差异显著外,其它17项表型指标均达到极显著水平,表明缙云山草珊瑚各居群间已经发生了明显的形态分化;居群内和居群间变异分别占总变异的60.7%和39.3%,说明居群内变异是表型变异主要来源,但居群间变异也不容忽视;欧氏距离聚类将所有居群划归为两大类群,主要与居群的群落类型与干扰程度有关;表型性状的Pearson相关性聚类显示草珊瑚同类性状在表型分化过程中具有很强的相关性。     

花粉和资源限制对青阳参坐果率的影响

以生长于自然种群的青阳参植株为材料进行补充授粉试验,以人工种植的青阳参植株为材料进行资源限制试验,探讨花粉和资源限制对青阳参坐果率的影响.结果表明:自花授粉、天然授粉和异株异花授粉植株的结实率分别为1.7％、2.25 ％和24％,花粉来源对青阳参坐果存在显著影响;补充施肥和不补充施肥植株的坐果率分别为5.12％和3.1...     

Dispersion patterns of Diachasmimorpha longicaudata (Hymenoptera: Braconidae) in citrus orchards in southeast Brazil

We studied the dispersion patterns of the exotic endoparasitoid, Diachasmimorpha longicaudata (Ahsmed) (Hymenoptera: Braconidae), in 1999 (summer) and in 2000 (winter) in a citrus orchard in southeast Brazil. Different population densities of D. longicaudata were released in the centre of the orchard, and their dispersion was determined by using yellow, sticky, rectangular traps, placed in various distances and heights around the release point. Our results suggest that during summer, climatic conditions did not affect dispersion. However, in winter, dispersion rates were positively affected by temperature, and negatively by rainfall. Both estimated dispersal distance and surface were higher in summer than in winter for all release densities. Dispersion peaked at 2000 parasitoids ha^?1 in summer and 8000 parasitoids ha^?1 in winter. The importance of our results for the biological control of fruit flies by augmented or innoculative releases of D. longicaudata in southeast Brazil is discussed.     

脂氧合酶、茉莉酸和水杨酸对猕猴桃果实后熟软化进程中乙烯生物合成的调控

20℃下后熟果实的LOX活性增加先于自由基产生和乙烯生成;JA处理对果实后熟软化启动期(采后1d)和果实快速软化期(采后5d)果实切片中的LOX活性、自由基产生和乙烯生物合成有促进作用,至果实软化后期(采后7d)这种效应消失;亚油酸只在采后1d果实切片中促使LOX活性和乙烯生成;SA处理抑制了果实后熟进程中组织切片的LOX活性、自由基产生和乙烯的生物合成;SA和JA对LOX活性和乙烯生物合成具有明显的拮抗作用。     

Factors affecting in vitro shoot proliferation and ex vitro establishment of mangosteen

Shoot proliferation has been achieved in Garcinia mangostana L. using seed explants. Maximum mean number of shoots per explant (16.8) was obtained from cultures on Murashige and Skoog medium supplemented with 40 mM 6- benzyladenine, and 2.5 mM -naphthaleneacetic acid and kept at 30 °C under an 8 hour photoperiod. Cultures on the same medium but supplemented with 2 g l^-1 activated charcoal produced fewer shoots. However, growth of these shoots was more organized and 75% rooting was obtained. Woody Plant Medium was not a suitable medium for shoot proliferation. Ex vitro establishment was best obtained on planting medium consisting of sand, soil and organic material (3:2:1).Abbreviations BA 6-benzyladenine - IBA indole-3-butyric acid - NAA -naphthaleneacetic acid - MS Murashige & Skoog (1962) basal medium - WPM Woody Plant basal medium (Lloyd & Mc Cown 1980)     

Polygalacturonase activity and variation in ripening of papaya fruit with tissue depth and heat treatment

Effects of tissue position (viz. outer vs inner mesocarp) and heat treatment (48°C, 20 min) on variations in polygalacturonase (EC 3.2.1.15 and EC 3.2.1.67) activity and ripening of fruits of Carica papaya L. cv. Backcross Solo were investigated. Polygalacturonase activity increased during ripening concomitantly with an increase in tissue softness and soluble polyuronide level. Throughout ripening, inner mesocarp tissue was softer and contained higher polygalacturonase activity than outer mesocarp tissue. Titratable acidity as well as ß-galactosidase (EC 3.2.1.23) activity also increased during ripening; however, unlike polygalacturonase, their level or activity was lower in inner than in outer mesocarp. Ascorbic acid could partially account for the increase in titratable acidity during ripening but contributed very little to the differences in titratable acid levels between outer and inner mesocarp. Heat treatment had no effect on either fruit softness or titratable acidity, but it markedly reduced the increase in ascorbic acid and polygalacturonase activity during ripening. Ripening, as reflected by changes in tissue softness and polygalacturonase activity, progressed outwardly from the interior towards the exterior of the fruit. The effect of heat treatment in suppressing polygalacturonase activity was relatively greater in inner than in outer mesocarp, suggesting that sensitivity of the enzyme to heat treatment may vary with stage of ripeness of the tissue.     

The possible involvement of polyamines in the development of tomato fruits in vitro

The apparent involvement of ornithine decarboxylase (ODC) and putrescine in the early stages of fruit growth in tomato (Lycopersicon esculentum Mill.) has been previously described. Further evidence presented here supports the direct involvement of ODC and putrescine in the cell division process in tomato fruits. In tomato fruits grown in vitro, in which basic growth processes are inhibited, the activity of ODC and arginine decarboxylase (ADC) and the level of free polyamines were reduced. While ODC and ADC activity was correlated with the period of cell division in the tomato fruit, the free polyamine content was correlated with the DNA content, cell size, and fruit fresh weight. The addition of exogenous putrescine, however, did not restore the basic growth processes in the fruits grown in vitro.     

A kinetic model of sugar metabolism in peach fruit reveals a functional hypothesis of a markedly low fructose‐to‐glucose ratio phenotype

The concentrations of sugars in fruit vary with fruit development, environment and genotype. In general, there were weak correlations between the variations in sugar concentrations and the activities of enzymes directly related with the synthesis or degradation of sugars. This finding suggests that the relationships between enzyme activities and metabolites are often non‐linear and are difficult to assess. To simulate the concentrations of sucrose, glucose, fructose and sorbitol during the development of peach fruit, a kinetic model of sugar metabolism was developed by taking advantage of recent profiling data. Cell compartmentation (cytosol and vacuole) was described explicitly, and data‐driven enzyme activities were used to parameterize equations. The model correctly accounts for both annual and genotypic variations, which were observed in 10 genotypes derived from an interspecific cross. They provided important information on the mechanisms underlying the specification of phenotypic differences. In particular, the model supports the hypothesis that a difference in fructokinase affinity could be responsible for a low fructose‐to‐glucose ratio phenotype, which was observed in the studied population.     

重庆大巴山区野生猕猴桃资源调查和遗传多样性分析

为探讨重庆大巴山区野生猕猴桃资源的分布现状和遗传多样性,进一步保护和挖掘有价值的野生种质资源,本试验在重庆大巴山野生猕猴桃聚集区开展实地调查、采集,重点分析该地区野生猕猴桃果实特异性和多样性。结果显示:重庆大巴山野生猕猴桃集中分布在海拔978~1758 m的高山上,以中华、美味及两者混杂类型分布为主,另有软枣、显脉和硬齿猕猴桃等野生资源分布,该区域以城口县野生猕猴桃资源最为丰富。果实性状分析显示了重庆大巴山野生猕猴桃有着丰富的表型性状多样性,SSR标记从DNA层面也印证了这一点。采集的41个野生资源按成熟期分类可分成3类:早熟资源5个、中熟资源34个和晚熟资源2个。有14个资源的可溶性固形物达到15%以上,4个资源的VC含量达到200 mg/100 g以上。另外,根据资源特异性筛选出5个有较高应用价值的野生资源。重庆大巴山地区蕴含的丰富野生猕猴桃资源可为猕猴桃人工驯化、品种改良提供种质资源。     

When Color Really Matters: Horticultural Performance and Functional Quality of High-Lycopene Tomatoes

Introgression of spontaneous or induced mutations has been used to increase the levels and diversify the profile of antioxidants in many fruits including tomato. The high-pigment (hp) and old-gold (og) alleles exemplify this approach as attractive genetic resources suitable to inbred elite high-lycopene (HLY) tomato lines with improved color and nutritional attributes. Although several studies have been published on HLY tomatoes, a systematic analysis of the information on their agronomic performances, processing features, and functional quality is lacking, leaving room for the assumption of their poor competitiveness with conventional tomato cultivars and limiting their agricultural diffusion. Therefore, the aim of this study is to critically review the most important agronomic, horticultural, and functional traits of HLY tomatoes, as well as the advances in some emerging (pre)industrial applications. Field experiments performed in different countries showed that most available HLY lines are productive, vigorous, with excellent foliage cover and with morphologically acceptable fruit. Tomato yield of HLY genotypes ranged from ～30 to ～178 t/ha exceeding, in some trials, that of highly productive cultivars. Red-ripe fruits of most HLY lines showed commercially suitable soluble solids and titratable acidity, in addition to increased levels of lycopene (up to 440 mg/kg fw) and other bioactive phytochemicals (mainly flavonoids and vitamin C) compared to their near isogenic conventional counterparts. Innovative (pre)industrial uses of HLY tomato include the following: (1) production of HLY sauces, juices, and powders; (2) supercritical-CO₂ extraction of lycopene containing oleoresins; and (3) preparation of lycopene rich micro- and nano-carriers with improved stability and specific tissue delivery. In turn, the use of these innovative high-quality ingredients in the formulation of lycopene fortified foods, cosmetic products, nutraceuticals, and pharmaceuticals has been proposed as the basis of a novel highly profitable tomato product chain.