致死低温确定法的改进及其在不结球白菜上的验证

本文以不结球白菜为材料,首次提出了计算低温处理后细胞膜伤害率的公式:MIP=100(Rt-C)/(K-C),改进了低温致死温度的确定方法。试验结果表明,处理温度与细胞膜伤害率之间的关系可以用Logistic方程Y=K/(1+a exp(bx))来描述,消除了本底干扰的拐点温度与植物组织的低温致死温度相一致。用本法测定的离体叶片组织及愈伤组织的抗冻性与田间植株抗冻性调查结果相一致。此方法可供其它植物抗冻性测定时参考。     

电导法测定鲜食葡萄的抗寒性

以1年生葡萄休眠枝条为试材,应用电导法研究了7个鲜食葡萄品种在不同低温下细胞膜透性的变化,配合Logistic方程求出拐点值,测定冰冻半致死温度(LT50)。结果表明,低温处理下,鲜食葡萄组织电解质渗出率增加呈S形曲线增长,在-15℃～-25℃之间随着温度的下降,葡萄组织电解质渗出率有一急剧升高的敏感区域;葡萄LT50在-13.9℃～-19.72℃之间;品种京秀、矢富罗莎抗冻性最强,美人指抗冻性最弱;提出了以电解质渗出率40.0%～52.0%相对应的拐点温度为枝条组织的临界致死温度。     

对氯苯氧乙酸对红地球葡萄低温霜害的影响

对红地球葡萄生长后期喷施4种不同浓度4-CPA,在不同低温胁迫下,用电导法测定细胞膜透性,配合Logistic方程求出拐点值,确定冰冻半致死温度(LT50).结果表明:低温胁迫下,红地球葡萄电解质透出率呈S型曲线增长,在0～-6℃间随着温度下降,葡萄叶片组织电解质透出率有一急剧升高的敏感区域,喷50 mg/L 4-CPA的抗寒性最强,拐点温度为-2.57～-2.90℃.     

乌塌菜新种质的抗冻性鉴定

为提高‘上海小八叶’乌塌菜在北方地区的抗冻性和露地越冬能力,采用抗冻性强的‘平度薹菜’与乌塌菜进行变种间杂交,以‘上海小八叶’乌塌菜为轮回亲本进行4代回交,从自交后代中选出抗冻性强的乌塌菜新品系‘5-15’和‘6-9’。本试验测定了新品系和亲本材料的露地越冬存活率、低温半致死温度以及叶绿素荧光参数综合性能指数PI_(total),以期了解新品系的抗冻性及露地越冬性。试验结果表明,乌塌菜新品系的露地越冬成活率显著高于‘上海小八叶’,2年平均存活率分别达到83%(‘5-15’)和90%(‘6-9’),与父本‘平度薹菜’无显著差异。室内抗冻性鉴定结果显示,乌塌菜材料‘5-15’和‘6-9’和‘平度薹菜’的低温半致死温度LT_(50)均达到-7℃以下,低于‘上海小八叶’;叶绿素荧光参数中的综合性能指数PI_(total)也反映出低温下乌塌菜材料‘5-15’和‘6-9’的光合性能要显著高于‘上海小八叶’。以上结果均表明乌塌菜新种质的抗冻性较其亲本‘上海小八叶’乌塌菜显著增强,通过对抗冻种质资源的杂交利用,可有效提高乌塌菜的越冬能力。     

低温胁迫对甜瓜幼苗膜透性及膜脂过氧化物的影响

以早金和伊丽莎白为试材,在人工气候箱控制条件下,研究了不同温度下(30℃/20℃(昼/夜,下同)、21℃/12℃、15℃/8℃)及低温持续时间对2种甜瓜幼苗叶片细胞膜透性、膜脂过氧化及保护酶系统的影响.结果表明:低温造成了甜瓜细胞膜伤害,15℃/8℃条件下,甜瓜的细胞膜伤害率、MDA含量高于30℃/20℃、21℃/12℃,细胞膜透性大,膜脂过氧化程度高;早金SOD、POD、CAT活性变化复杂,一定范围内随低温程度高而增强,超过一定范围后则随低温程度加剧而下降;各温度条件下,伊丽莎白膜伤害率、MDA含量和保护酶系统比早金稳定,因而具有较强的低温耐受性.     

杏品种花器官耐寒性研究

以杏２５个品种的花朵为材料，在低温下，通过测定花蕾和盛开花的电解质渗出率，配以Ｌogistic方程，结合组织褐变观察，确定的杏花蕾和盛开花的ＬＴ50（半致死温度）与实际 观察结果基本一致，杏花蕾抗低温温度为－７～１１℃，盛开花朵抗低温温度为－３～－６℃。丙二醛含量和乙烯释放量与其抗寒性有关。     

7个梨品种的低温半致死温度及耐寒性评价

【目的】研究梨品种半致死温度与耐寒性的关系及抗寒性水平,为杂交育种选择抗寒亲本及梨品种区域性引进提供科学依据。【方法】以1 a生梨苗休眠枝条为试材,应用电导法研究了7个梨品种在-20℃、-25℃、-30℃、-35℃、-40℃、-45℃低温下细胞膜透性的变化,配合Logistic方程,求得半致死温度(LT50),并与低温处理下的冻害指数进行相关性比较。【结果】供试梨枝条不同低温处理下电解质渗出率增加呈S形曲线,与相应的低温呈极显著负相关;供试梨品种的半致死温度为:‘苹果梨’-41.1℃、‘甘梨早8’-38.4℃、‘中梨1号’-38.2℃、‘美人酥’-35.3℃、‘玉露香’-34.8℃、‘黄冠’-30.7℃、‘丰水’-30.3℃;半致死温度与其相近温度处理的枝条冻害指数呈显著负相关;低温处理下,各梨品种枝条冻害部位表现不同,且对其伤害有一个跃变过程。【结论】半致死温度能准确反映梨品种的抗寒力;供试梨品种的抗寒力大小为:‘苹果梨’‘甘梨早8’‘中梨1号’‘美人酥’‘玉露香’‘黄冠’‘丰水’。     

不结球白菜抗冻性鉴定及其相关性状的研究

本试验以不结球白菜(Brassica campestris L.ssp.chinensis(L.)Makino)为材料,对不同地区的26个主栽品种和杂种一代在自然和人工条件下的抗冻性进行测定,探索抗冻性的鉴定技术及其相关性状。结果表明,不结球白菜的抗冻性与地理起源和发育特性有关,华南品种抗冻性较弱,华北品种及生育期晚的品种抗冻性较强。不同类型的不结球白菜中,菜薹类(var.tsai-tai Hort.)的抗冻性较弱,薹菜类(var.tai-tsai Hort。)的抗冻性较强。杂种一代受冻后恢复能力较强。低温锻炼后叶片中可溶性糖含量与抗冻性呈正相关。不结球白菜的抗冻性鉴定宜将测定低温致死温度和田间抗冻性试验相结合。杂种优势利用是不结球白菜抗冻育种的有效途径之一。     

梨矮化砧抗寒力试验研究

取1 a生苗为试材,进行-20、-25、-30、-35、-40、-45℃低温处理,用电导法配合Logistic方程,求得拐点(LT50),即半致死温度,并与自然气候条件下的冻害级别进行相关比较,鉴定中矮1号等6个矮化和半矮化砧木的抗寒能力.结果表明:电解质渗出率呈典型的S型曲线,与相应的低温呈极显著负相关;鉴定出供试砧木的抗寒力;半致死温度与田间冻害级别相关程度达极显著水平.     

以电导法配合Log istic方程确定茶梅‘小玫瑰’的抗寒性

 摘　要: 以不同处理时间、不同低温处理下茶梅‘小玫瑰’叶片的电解质外渗率(REC) 变化作曲线,并结合Logistic方程分别计算茶梅的半致死温度(LT50 ) , 结果发现在低温处理6 h以上, 茶梅叶片的REC均随着处理温度的降低而呈“S”形上升, 由此计算出“S”形拐点对应的温度即为茶梅叶片的LT50 , 其温度值在- 1215℃至- 14℃之间, 这可认为是茶梅抗寒能力的重要指标。关键词:     

Effect of temperature on seed and fruit development in three mango (Mangifera indica L.) cultivars

The effect of diurnal maximum/minimum (20/10 or 25/15 °C) temperatures on seed and fruit development of ‘Irwin’, ‘Kensington’ and ‘Nam Dok Mai’ mangoes (Mangifera indica L.) was studied in a controlled-environment glasshouse. Exposure to low temperatures (20/10 °C day/night) 3 days after hand pollination significantly increased the percentage of stenospermocarpic fruit (nubbins), in which embryos were aborted at some stage during early fruit development. There were significant differences between cultivars in the percentage of nubbins produced out of the total fruit set following overnight exposure to 10 °C with 21% for ‘Nam Dok Mai’, 11% for ‘Kensington’ and 3% for ‘Irwin’. At 45 days after pollination, nubbin fruits were much smaller in size and weighed ca. 50% less than normal fruits. The lower percentage of nubbin fruits in ‘Irwin’ implies a greater adaptation to cool temperatures by this cultivar during fruit set and early embryo development.     

Optimization of agrotechniques in the cultivation of Luffa acutangula

Germination requirements, flowering pattern, planting density and growing regimes were examined for Luffa acutangula (L.) Roxb. Maximum germination (50%) was obtained at 35°C, and at 8, 12, and 45°C germination was completely inhibited. Partial removal of the seed coat increased the percentage of germination while vernalization and exposure to salinity 5=50 mM NaCl reduced it. Planting season influenced flowering pattern, with significantly more female flowers being produced in spring-summer (long days and high temperatures) than in autumn-winter (short days and low temperatures). A high yield of 44.5-47.3 Mg ha 1 was obtained for plants trained on trellises at planting densities of 10,000 and 20,000 plants ha-1. Fruits kept at low temperatures showed the least deterioration during storage, a shelf life of about two weeks being demonstrated at 4°C.     

Florogenesis of the Mediterranean geophyte Narcissus tazetta and temperature requirements for flower initiation and differentiation

Plant florogenesis is determined by the interaction between the genetics of the individual plant and environmental factors. Flower initiation and development of many studied plant species require low temperatures. However, some geophytes form flowers within the bulb during the summer quiescence period and do not require low temperatures for florogenesis. Narcissus tazetta was employed to study, in detail, the stages of flower development during the summer period, with special emphasis on the effect of temperature on inflorescence initiation. The sequence of morphological processes occurring during floral initiation and development was observed by SEM. During 3 years, the bulbs were subjected to different storage temperatures during the summer, and records were taken of the percentage of apical meristems that shifted from vegetative to reproductive development. Flowering and inflorescence quality were recorded after planting. It was concluded that, under natural conditions, the temperature increase in June, during the growth of the mother plant, leads to the transition of the apical meristem to the reproductive stage. Floral initiation and reproductive development in N. tazetta is promoted by high temperatures with an optimum of 25 °C. Sub- and supra-optimal temperatures (20 and 30 °C) delayed differentiation, while lower temperatures (12 °C) inhibited florogenesis completely.     

‘三月红’荔枝不同温度处理的成花效应

利用控温室研究‘三月红’荔枝(Litchi chinensis Sonn.)成花诱导期和形态分化期不同的温度对成花的影响。结果表明,诱导期较低温(15℃/8℃,昼12h/夜12h),或者中度低温(18℃/13℃)处理,转移到高温(28℃/23℃)条件下,植株成花枝率低,而且也减少了每穗花的小花数和雌花质量。诱导期18℃/13℃,形态分化期15℃/8℃有利于成花。与18℃/13℃和15℃/8℃下发育的花芽相比,28℃/23℃下发育的花芽玉米素(ZRs)含量较低,而生长素(IAA)含量较高。高温处理下花芽中荔枝LEAFY同源基因(LcLFY)表达明显弱于低温处理。对不同温度下的成花与激素,以及与LcLFY表达的关系进行了分析讨论。     

茗葱种子萌发的生态学特性研究

以茗葱种子为试材,对其种子萌发生态特征进行研究。结果表明:茗葱种子含水量达7.97%;四唑(TTC 0.1%)染色测种子的生活力为(80.8±2.3324)%;不同温度下茗葱种子发芽进程缓慢,20℃为发芽最适温度,发芽率达(84.00±6.00)%,与其它温度差异显著;光照与否对种子的发芽率及发芽势不具有显著差异。     

The influence of light intensity,temperature and carbon dioxide concentration on anthocyanin content and blueing of ‘Baccara’ roses

The effect of light intensity, temperature and CO₂ concentration on anthocyanin content, blueing of flowers and size of flower buds was examined in ‘Baccara’ roses. Reflectance percentage at 425 nm was found to be an accurate measure of petal blueing. Reflectance was higher as the degree of blueing (determined by subjective estimation) increased and pigmentation decreased. During the first stage of development of the flower branch (elongation stage) temperature and light intensity had no effect on blueing. During Stage 2 of development (main stage of bud development), high temperatures and low light intensities caused blueing, whereas low temperatures during this stage, even at low light intensities, prevented blueing. Blueing was associated with low concentrations of CO₂ (0–100 vpm) as well as darkness. High concentrations of CO₂ (1500–3000 vpm) prevented blueing and increased pigmentation and flower size. The effectiveness of CO₂ in preventing blueing is related to high light intensities.     

Methods for testing the fertility of tomato pollen formed at low temperature

A reliable indication of pollen fertility is the number of seeds per fruit produced following artificial pollination, but this method is laborious, and very slow because sampling needs ripe fruits. To seek faster techniques to test the fertility of tomato pollen produced at low temperatures, we cultivated a large collection of tomato cultivars and lines of related wild species under cold conditions with minimum nocturnal temperatures below 10°C. We compared numbers of seeds per fruit with: number of pollen tubes at the base of the style, index of natural fruit-set, percentage of pollen grains stained with acetocarmine, percentage of pollen grains giving fluorochromatic reaction with fluoresceine diacetate, and percentage of pollen grains which germinated in vitro. All these variates correlated positively and significantly between themselves. The number of pollen tubes at the base of the style most closely correlated with number of seeds. This technique is equally laborious, but is good for precise testing of small numbers of genotypes and results are quickly available. Both acetocarmine staining and fluorochromatic reaction were simple, fast techniques with potential for screening large collections to detect genotypes with highly fertile pollen at low temperature; acetocarmine was the best, but neither test would identify genotypes with low-fertile pollens. Index of natural fruit-set and germination in vitro did not effectively determine the fertility of pollen produced at low temperature.     

冰川红叶小檗和紫叶小檗抗寒性对比分析

以冰川红叶小檗和紫叶小檗当年生枝条为试验材料,于12月和3月测定其7个处理温度(4℃、-10℃、-20℃、-30℃、-35℃、-40℃、-50℃)下的相对电导率、电阻抗参数值以及3个处理温度(-10℃、-20℃、-40℃)下的萌芽率,并对电导法、电阻抗图谱法及恢复生长法的测定结果进行相关性分析。结果表明,不同低温处理下的冰川红叶小檗当年生枝条的相对电导率均低于紫叶小檗;12月份冰川红叶小檗当年生枝条用相对电导率,胞外电阻率(r e)及低频电阻率(r 1)拟合的半致死温度分别为-34.84℃、-31.46℃和-29.47℃,紫叶小檗拟合的半致死温度分别为-28.37℃、-27.12℃和-26.07℃。3月份冰川红叶小檗当年生枝条用相对电导率,胞外电阻率(r e)及低频电阻率(r1)拟合的半致死温度分别为-31.94℃、-29.94℃和-27.98℃,紫叶小檗拟合的半致死温度分别为-26.84℃、-26.08℃和-25.43℃,证明冰川红叶小檗的半致死温度均低于紫叶小檗的半致死温度;12月份不同低温处理下的当年生枝条冰川红叶小檗的萌芽率为85.79%、74.33%和14.77%,紫叶小檗的萌芽率为75.74%、57.65%和8.06%;3月份不同低温处理下的当年生枝条冰川红叶小檗的萌芽率为88.80%、77.77%和16.16%,紫叶小檗的萌芽率为78.92%、68.37%和12.38%。由此表明,冰川红叶小檗的萌芽率均高于紫叶小檗,冰川红叶小檗的抗寒性高于紫叶小檗。     

提高桂花种子发芽率的研究

采取多种措施处理桂花种子,提高桂花种子发芽率.结果表明:4月中下旬收种(树上采摘)较为适宜;带皮桂花种子发芽率低,仅为9.0%;除去外果皮及果肉带壳桂花种子发芽率较高,达到43.7%,去壳后桂花种子发芽率为42.0%,GA3处理在10～100 mg/L浓度范围内浓度越高效果越好;经低温层积处理后播种的桂花种子,由于有腐烂现象,其发芽率偏低.     

Effects of suboptimal low temperature on yield,fruit appearance and quality in muskmelon (Cucumis melo L.) cultivars

Summary

The effects of suboptimal low temperature were investigated on an array of yield, fruit appearance and fruit quality characters in 23 cultivars of melon, Cucumis melo L. The cultivars were grown in two temperature regimes: (I) a heated greenhouse (T1) with temperatures similar to those used in commercial cultivation in the winter in Israel; and (ii) an unheated greenhouse (T2) that had significantly lower night temperatures than T1. Significant differences were found among the cultivars in all characters. Plants from T2 showed an extended fruiting period, more fruits and higher total yield but smaller and lighter fruits than in T1. Fruits from T2 also had significantly more netting and higher amounts of total soluble sugars (TSS), sucrose and fructose than fruits from T1. Hybrid cultivars showed significantly higher electrical conductivity (EC), pH, acidity, TSS, sucrose, fructose and total sugars than open pollinated cultivars. Three trends were found among the characters in respect to the performance of the cultivars between T1 and T2: (a) most cultivars had significantly higher amounts in T2 than T1 (fruit/plant, yield/plant and fructose); (b) only cultivars with amounts below the pooled mean in T1 had higher amounts in T2 (percent dry weight, sucrose, TSS and total sugars); (c) no trend was found between T1 and T2 (mean fruit weight, pH, EC, glucose). Suboptimal low temperatures, when used appropriately, can aid in improving fruit quality.