~(60)Coγ射线诱发梨的短枝型变异的探讨

本文对苹果梨、朝鲜洋梨辐射营养后代的短枝型变异进行了研究。研究结果表明:辐射有利于培育短枝型品种。在本试验范围内,辐射处理均有不同程度的矮化,而且与对照差异极显著。朝鲜洋梨较苹果梨对辐射处理更敏感。采用辐射诱变矮化型品种,可在V_1代直接进行选择。     

山茶花Camellia japonicalL辐射诱变效应

本试验用~(60)Co γ射线处理山茶花的嫩枝插条,1年生小苗和3—4年生植株,研究其辐射敏感性和诱变规律。结果表明,嫩枝插条的适宜剂量范围为1—3krad,成长植株宜控制在2krad以下。不同品种对射线敏感性不同,所引起的花色、花型突变频率亦不同,其辐度在2.5—12.0％。经3年选育,已获得观赏价值高的突变体。     

设施油桃膨大期摘心和疏果对根外追15N的运转与分配的影响

以设施栽培的5年生"早红珠"油桃/毛桃为试材,应用15N示踪技术研究果实膨大期摘心、疏果处理对油桃叶片15N -尿素的吸收、运转及分配规律的影响.结果表明:疏果、摘心处理可不同程度降低叶施15N的利用率,各处理间差异显著,且15N在树体内的运转、分配随生长中心的转移而转移.摘心增加了15N同化物向果实、短梢的分配率,减少了向长梢的分配率;摘心7 d后15N同化物向多年生枝的分配率比对照稍大,但向2年生枝的分配率却远大于对照,此时摘心株大枝NdFF%也表现出类似的趋势.疏果处理增加了15N同化物向梢顶嫩叶和长梢的分配率,减少了向果实和短梢的分配率;疏果处理向多年生枝的分配率与对照相比并无太大差异,但向2年生枝的分配率远小于对照.本研究可为制定油桃丰产技术提供理论依据.     

不同类型红富士苹果对春季土施~(15)N-尿素的吸收、分配和利用特性研究

以15年生"惠民短枝"(短枝型)和"长富10"(普通型)红富士苹果/平邑甜茶(M.domesticaBorkh.cv.RedFuji/M.hupenensisRhed)为试材,研究其对春季土施15N-尿素的吸收、分配与利用特性。结果表明,盛花期短枝型和普通型红富士均以细根中吸收的氮素来源与肥料的比例(Ndff)值最高,分别为0.407%和0.286%,短枝型显著高于普通型;新梢旺长期和花芽分化期,根部吸收的15N优先向新生营养器官运转,短枝型红富士,除叶片外,其余各器官中Ndff值均高于普通型;果实膨大期和果实采收期,短枝型和普通型红富士均以果实中Ndff值最高,短枝型高于普通型;采收后,短枝型和普通型红富士均以粗根中Ndff值最高,分别为0.902%和0.792%,短枝型高于普通型。不同物候期短枝型和普通型红富士吸收的15N在各器官的分配率存在差异,盛花期贮藏器官15N分配率最高,两品种差异不显著;新梢旺长期和花芽分化期,短枝型和普通型红富士贮藏器官15N的分配率不断下降,15N主要向营养器官分配,短枝型低于普通型;果实膨大期和果实采收期短枝型和普通型红富士生殖器官成为新的分配中心,短枝型显著高于普通型;采收后15N向贮藏器官回流、积累,短枝型红富士贮藏器官能积累更多的营养物质。春季土施15N-尿素,随着物候期的推移,短枝型和普通型红富士对15N尿素的吸收利用率逐渐上升,采收后达到最高,分别为24.643%和16.311%;短枝型红富士氮素利用率普遍高于普通型。     

重离子对春小麦诱变育种及生物效应的研究

采用不同离子种类及不同能量的重离子对 1 0个春小麦品种 (系 )的 3 0 1次诱变处理 ,经过 4年 6代的选择。选育出较原亲本具有突出表现的稳定突变系 59份和3个优突变系 ,获得了不同能量和不同离子种类的辐照适宜剂量范围及定点 (位 )诱变处理的突变频率。     

~(60)Coγ射线与GA_3复合处理对番木瓜的遗传诱变效应研究

研究了60 Coγ射线与GA3 复合处理对番木瓜的遗传诱变效应 ,结果表明 ,经 1 0～ 40Gyγ射线处理 ,幼苗根尖细胞的微核细胞率、染色体畸变率、叶片畸变频率随剂量增大而增大 ,花粉育性下降 ,结果推迟 ;用 1 0～ 5 0mg L的GA3 处理可有效减轻辐射损伤 ,低辐射剂量时以低浓度的GA3 处理效果明显 ,而高辐射剂量时以高浓度的GA3 处理效果明显     

咖啡因对辐射效应的影响

用咖啡因或咖啡因与γ射线复合处理大麦种子,研究咖啡因对大麦辐射效应的影响及其作用机制,从而找出辐射育种中正确应用咖啡因的技术方法。研究结果表明,咖啡因作辐照前处理或辐照后处理均可增加辐射损伤;前处理的辐射损伤此后处理更严重,均随咖啡因溶液浓度的增加而增加;在γ射线和咖啡因的复合处理中,咖啡因溶液浓度在1.164mg/ml以下,作用机制是抑制辐射损伤的修复,当浓度达到1.164mg/ml时,咖啡因效应包括抑制辐射损伤修复和本身引起的诱变作用。在辐射育种工作中,咖啡因浓度以1mg/ml为宜。     

少核沙田柚的辐射选育研究

用6 0 Coγ射线处理沙田柚休眠接穗 ,选育出优良变异枝系 95 7 2。该变异枝系平均单果种子数为 1 0 2粒 ,单果重为 1 1 50g,丰产性和果实其它品质特性基本上保持沙田柚的优良特性。对该变异枝系的花粉育性和染色体行为观察结果表明 :辐射诱发染色体变异 ,分裂不正常 ,导致花粉和胚胎败育 ,产生二倍体水平的无核突变。     

辐照对苦荞种子发芽及苗期细胞膜与保护酶活性的影响

利用不同剂量(100~500Gy)的60Coγ射线辐照处理3个苦荞品种的干种子,研究γ射线对苦荞幼苗的性状、膜透性和保护酶活性的生物学效应。结果表明,3个苦荞品种的发芽率、苗高、根长随着辐照剂量的增加逐渐降低,细胞膜透性、丙二醛含量、SOD酶活性和POD酶活性则逐渐增加,但在0~300Gy剂量辐照范围内的晋荞2号和九江苦荞的SOD酶活性呈现增加-降低-增加的趋势。γ射线对不同品种各性状产生的影响程度也不同,3个品种辐照敏感性依次为九江苦荞>西农1号>晋荞2号。     

低剂量γ辐射诱导作物种子超弱发光研究

用20 Gy 、30Gy 和40Gy 60Co γ射线照射黄瓜种子,用10Gy 、20 Gy 和40Gy 剂量照射番茄种子,在停照后6 、12 、24 、48 和72h 测量干种子和萌动种子超弱发光强度。结果表明,在低剂量辐照范围内,超弱发光强度随辐照剂量增大而增大,种子萌动期发光强度大于干种子,经10Gy 处理的番茄种子发光强度一直高于其它处理及对照组。     

高能重离子束和X射线辐射水稻幼苗的当代生物学效应研究

为探究高能重离子束和X射线辐射对水稻幼苗生长发育和生理特性的影响,使用5~40 Gy的高能碳离子束和10~80 Gy的X射线辐射处理粳稻Kitaake幼苗,测定根长、芽长、苗高、株高、分蘖数、结实率、千粒重、光合特性、抗氧化酶活性及遗传物质多态性指标。结果表明,高能重离子束或X射线辐射水稻幼苗后,其根长和芽长均呈现随辐射剂量增加而降低的趋势,但存活植株成熟期的株高与未辐射组相比差异不显著;M₁植株结实率及种子千粒重随剂量升高呈下降趋势,在较高剂量下表现为显著降低。辐射处理后相对根长约为69%时,两种辐射对幼苗的根及芽在较短时间内的抗氧化系统存在显著影响。与未辐射组相比高能碳离子束辐射组的叶绿素含量和F_v/F_m值均无显著差异,而X射线辐射处理组的叶绿素含量较高、F_v/F_m值降低。20 Gy高能碳离子束辐射处理水稻幼苗简单重复序列间扩增(ISSR)多态率为29.31%,40 Gy X射线辐射处理水稻幼苗ISSR多态率为37.76%。本研究结果为不同电离辐射处理水稻幼苗提供了推荐的诱变剂量区间:高能碳离子束20~30 Gy,X射线30~40 Gy。     

苹果受精着果机理研究初报

用气相色谱（ＧＣ）测定了ＰＰ３３３，ＧＡ３处理及未处理苹果果实，果台副梢中内源ＧＡ３，ＧＡ４＋７，ＡＢＡ，ＩＡＡ，Ｚ和ＺＲ的含量，用质谱（ＭＳ）测定了＾１５Ｎ的分配运转。结果表明，ＰＰ３３３处理明显地增加主要座果率，抑制果台副梢的增长。而ＧＡ３则具有增大果径和促进果台副梢生长的作用，内源细胞分裂素的含量与苹果能力相吻合，其它激素含量的多少与着果没有是有显相关。多效唑（ＰＰ３３３）处理明显地提高了内     

不同种类蔬菜苗期对镉的敏感性研究

产地环境中镉（Cd）对蔬菜的影响主要表现为蔬菜可食部分超标,高浓度时影响其生长发育,基于评述蔬菜幼苗对Cd的敏感性是按其对Cd的吸收累积量来排序,累积Cd量越高定义为该蔬菜幼苗对Cd越敏感,采用水培方法,探讨了Cd对小白菜（叶菜）、黄瓜、豇豆（果菜）和萝卜（根菜）幼苗吸收累积量及生长发育的影响。结果表明,蔬菜幼苗根和茎叶中累积Cd量均随Cd处理浓度的增加而显著增加（P〈0．05）。同一处理浓度下根中Cd含量远高于茎叶中Cd含量,根和茎叶对Cd的累积强弱顺序也即蔬菜苗期对Cd的敏感性排序为小白菜〉萝卜〉黄瓜〉豇豆;随Cd浓度增加,叶片中叶绿素含量降低,过氧化氢酶（CAT）含量升高;蔬菜出苗率、幼苗根长、植株鲜重显著降低。     

Postharvest polyamine application alleviates chilling injury and affects apricot storage ability

Fruit of two apricot cultivars 'Bagheri' and 'Asgarabadi' were treated with putrescine (Put) or spermidine (Spd) at 1 mM and then were stored at 1 °C for 21 days. Fruit were sampled weekly and stored 2 days at 20 °C for shelf-life study. The treatments reduced ethylene production and maintained the firmness and color of the fruit. Peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), and polyphenol oxidase (PPO) activities and total phenol (TP) concentrations were measured during storage. Both cultivars showed chilling injury (CI) incidence, and the severity in control fruit was higher than either Put or Spd treatments. CI incidence in Spd-treated fruit was lower than that of Put-treated fruit. Polyamine (PA) treatment generally increased antioxidant enzyme activity of fruit during storage. PA treatments may help maintain the quality of apricot fruit during storage by inhibiting ripening and decreasing CI incidence.     

施氮水平和打顶后涂抹NAA 对盐渍土壤上长绒棉铃脱落和产量的影响

为探讨减少盐碱地棉花铃脱落的途径, 田间条件下研究了土壤供应低氮(N 226.5 kg·hm^-2)和高氮(N 346.5 kg·hm^-2)条件下, 不打顶、打顶和打顶后涂抹生长素对棉花铃脱落和产量构成因素的影响。结果表明, 低氮和高氮水平下, 打顶、打顶后涂抹NAA 处理果枝落铃率都低于不打顶处理。打顶后涂抹浓度为0.3 mmol·L^-1 的NAA 处理在低氮水平下的成铃率比传统打顶处理高1.3 个百分点, 而铃脱落率比传统打顶处理低0.8 个百分点, 皮棉产量比传统打顶处理高23.7%。高氮水平下, 与传统打顶处理相比, 打顶后涂抹浓度为3 mmol·L^-1 的NAA 单株成铃率、铃脱落率、皮棉产量之间差异不显著。在同一处理中, 高氮水平的单株成铃数、单铃重和吐絮数均低于低氮水平, 而衣分无明显差异, 从而导致皮棉产量下降。上述结果说明, 打顶后涂抹一定浓度的NAA 可增加棉花单株现铃、成铃、吐絮数, 增加单铃重, 降低落铃率, 从而提高产量, 而过量施用氮肥会导致产量下降。     

Relationships between leaf and fruit minerals and fruit quality attributes of apples grown under northern conditions

Field experiments were conducted during 1994–1995 in seven apple (Malus spp.) orchards located in the southwest of Finland (the mainland and the Åland Islands). The cultivars were ‘Transparente Blanche’, ‘Samo’, ‘Melba’, ‘Raike’, ‘Red Atlas’, ‘Åkerö’, ‘Aroma’, and ‘Lobo’. Leaf samples from branches bearing fruits (BF) and not‐bearing fruits (BNF) were collected two times during the growing seasons. Fruit samples were picked about one week before commercial maturity. Macronutrient concentrations in fruits and leaves, fruit diameter and juice pH, titratable acidity (TA) and soluble solids concentrations (SSC) were determined. Leaf nitrogen (N), phosphorus (P), and potassium (K) were higher, but calcium (Ca) and magnesium (Mg) were lower in BNF. Branch types (BF and BNF) were closely related in leaf N, P, and Ca, but not in leaf K and Mg at the first sampling time. Fruit N, P, K, and Mg were closely related to each other but not to fruit Ca. Mean fruit N and Ca and leaf P and Mg were low compared with the recommended levels. Relationships between fruit and leaf nutrient concentrations were found only in P and Mg. Fruit diameter increased and juice SSC decreased with increasing leaf N concentration. Fruit P declined with increasing fruit diameter and juice TA increased and SSC/TA decreased with increasing leaf P and Ca concentrations.     

Salt tolerance of Casuarina equisetifolia and Frankia Ceq1 strain isolated from the root nodules of C. equisetifolia

Effects of NaCl on the seed germination and growth of Casuarina equisetifolia seedlings and multiplication of the Frankia Ceq1 strain isolated from the root nodules of C. equisetifolia were examined. The germination rate of the seeds markedly decreased as the NaCl concentration increased and germination did not occur at 300 mM NaCl. The fresh weight of both shoots and roots of the seedlings treated with NaCl for 6 weeks apparently decreased as the NaCl concentration increased. However, root nodules were formed by inoculation with the Frankia Ceq1 strain in some seedlings treated with 300 mM NaCl and the viability of the seedlings at 500 mM NaCl was almost the same as that of the seedlings not subjected to the NaCl treatment. The Na⁺ concentration in the shoots sharply increased with the elevation of the NaCl concentration in the ambient solution, but the level was approximately 300 mM even in the seedlings treated with 500 mM NaCl for 6 weeks. On the other hand, the increase of the Na⁺ concentration in the roots by the NaCl treatment was much smaller than that in the shoots and the level was less than 150 mM. The growth of the free-living Frankia Ceq1 strain was approximately linearly suppressed as the NaCl concentration in the medium increased and the hyphae became somewhat thicker and shorter or disintegrated in the medium containing NaCl at a concentration above 150 mM. The Na⁺ concentration in the cells increased as the NaCl concentration in the medium increased, but the level was maintained at less than 30 mM even in the medium containing 500 mM NaCl. The cells whose growth was suppressed by the NaCI treatment grew actively again at almost the same rate as the control cells (not subjected to the NaCl treatment) when they were transferred to NaCl-free medium. These results strongly suggested that both C. equisetifolia seedlings and Frankia Ceq1 strain are highly tolerant to salt and this symbiotic system is useful for the recovery of the vegetation in areas with severe salt accumulation.     

Effects of NaCl salinity on miniature dwarf tomato ‘Micro‐Tom’: II. Shoot and root growth responses,fruit production,and osmotic adjustment 1

The growth and production of miniature dwarf tomato selection Lycopersicon esculentum ’Micro‐Tom’ plants grown from seedling to harvest in solution batph culture’ at four different NaCl salinity levels (2.4 [control, no NaCl], 7.6, 12.8, or 18 dS‐m^‐1 solution conductivities) was monitored. Incremental reductions in canopy extent and shoot area of ‘Micro‐Tom’ were observed with increasing solution NaCl level. Root growth and shoot height were somewhat less responsive to imposed salinity. Fruit number, fruit size, and leaf tissue osmotic potential decreased as NaCl concentration increased. Fruit yield was highly correlated with total canopy and shoot area, but not with tissue osmotic or total water potential. ‘Micro‐Tom’ plants survived and continued fruit production at higher salinity levels despite reduced canopy growth. Treatment effects on vegetative growth and fruit production became more pronounced later in the growth cycle.     

Interactions of Salinity Stress and Flower Thinning on Tomato Growth,Yield, and Water Use Efficiency

This study was conducted to investigate the effects of salinity stress and flower number on growth, yield, water use efficiency (WUE), and fruit quality of cherry tomatoes cultivated under soilless conditions. The experiment was conducted in a plastic house (5-m wide × 11-m long) located in Gifu University. The seedlings were transplanted in a randomized complete block design with six plants per treatment (NT1 and ST1 were with four plants), giving a total of 44 plants in 22 pots (two plants per pot). Two different salinity levels [no-salinity and salinity with electrical conductivity: 0.8 and 3.0 dS m^?1, respectively] and four flower number treatments (8, 13, 18, and free per truss) were investigated in the experiment. The results showed that salinity stress negatively affected tomato growth, yield, and marketable yield, but improved tomato fruit quality. The number of flowers had no effect on tomato growth variables and WUE, but the yield significantly increased with increasing flower number. However, the fruit quality was decreased with increased flower number. A reasonable control for fruit load can increase marketable yield in commercial cultivation. Under salinity stress conditions, properly increasing the number of flowers can avoid yield reduction.     

Effect of dips in a 1-methylcyclopropene-generating solution on 'Harrow Sun' plums stored under different temperature regimes

The effect of postharvest dips in a 1-methylcyclopropene-generating solution of the formulation AFxRD-038 (Rohm & Haas) on plum fruit (Prunus salicina Lindell cv. 'Harrow Sun') quality and ripening during storage was determined. Fruit weight loss, tissue firmness, soluble solids content (SSC), titratable acidity (TA), ethylene production, respiration, and the activities of the cell wall modifying enzymes polygalacturonase (PG), 1,4-beta-D-glucanase/glucosidase (EGase), beta-galactosidase (beta-gal), and pectin methylesterase (PME) were measured. Fruit reddening, anthocyanin content, and phenylalanine ammonia-lyase (PAL) activity were also analyzed. The 1-MCP-treated fruit showed reduced ethylene production and respiration rate and delayed softening, which was associated with the reduction in the activity of PG, EGase, and beta-gal. The immersion in 1-MCP-generating solutions also decreased weight and acidity loss without modifying the fruit SSC. The immersion treatment was particularly effective in the fruit stored at 5 degrees C, keeping higher overall quality, maintaining lower levels of anthocyanins and PAL activity, and preventing flesh reddening. The present data show that beneficial effects in delaying plum fruit ripening and controlling chilling injury can be obtained by dipping the fruits in a solution of this novel 1-MCP-generating formulation.