籼稻明恢63成熟种子愈伤组织的诱导及转基因水稻的抗性检测

利用不含附加营养成分的2,4-D培养基（2mg/L）诱导明恢63的成熟种子,9天预诱导后获得了大量的愈伤组织。利用基因枪辅助的土壤农杆菌转化法将天花粉蛋白（Trichosanthin, TCS）基因转入籼稻明恢63的愈伤组织,并通过再生（含有3mg/L 6-BA, 0.5mg/L ABA和1mg/L NAA的N6培养基）获得了转基因植物。 Southern blot分析和Western blot检测证明外源基因已经插入到T0代明恢63的基因组中并获得了表达。初步研究结果表明,转基因水稻对稻瘟病菌侵染具有抗性。     

水稻种子植酸含量的地域差异

植酸及植酸盐是种子中普遍存在的物质。植酸是肌醇六磷酸脂,谷物种子中的磷大部分以这种形式贮存于皮层、胚,尤其是糊粉层中,它在细胞中主要存在于蛋白体内。在油质种子中植酸的含量很高［１］,且在相同的生态条件下含量恒定［２］。有作者认为,杂交水稻种子中植酸的含量主要受母体基因型控制［３］。但是,同一品系水稻在不同地域栽种后,其种子植酸含量的差异则未见研究报道。本文就这方面的问题进行了初步研究。１　材料与方法１．１供试材料　进行实验栽种的水稻品系共有１９个,分别为湖北大学生命科学学院选育出的Ｒ１８．Ｒ３２…     

籼粳稻杂交后代的剑叶气孔性状与亚种特性的关系

水稻品种‘秋光’和‘七山占’的杂交后代F9群体,用TM1000台式扫描电镜观察水稻剑叶气孔各种性状的结果表明：籼粳杂交后代剑叶的气孔性状间变化规律不同,背部气孔密度大于腹部,背部气孔长度小于腹部,而气孔宽度则是背部大于腹部。杂交后代按照程氏指数分为籼稻、偏籼稻、偏粳稻、粳稻4种类型,它们的叶片背部气孔密度大小依次为粳型〉偏籼型〉偏粳型〉籼型;腹部和背部气孔密度的变化规律相一致。背部气孔长度依次为偏粳型〉偏籼型〉籼型〉粳型;腹部气孔长度变化为籼型〉偏粳型〉偏籼型〉粳型;背部气孔宽度变化为粳型〉偏粳型〉偏籼型〉籼型;腹部气孔宽度变化为偏粳型〉偏籼型〉粳型〉籼型。     

Differences in the Effects of Dehusking during Formation of Seeds on the Germination of Seeds of Indica and Japonica Rice (Oryza sativaL.)

Differences in germination of intact and dehusked seeds of two japonica and two indica cultivars of rice (Oryza sativaL.) were examined during the development and maturation of seeds both under high-temperature (30/23°C) and low-temperature (20/13°C) regimes and a 14-h photoperiod in growth cabinets. As described previously for seeds grown in the paddy fields, germination of freshly harvested japonica rice seeds that developed and matured in growth cabinets was inhibited by dehusking. We observed a roughly consistent triphasic pattern with respect to the germination of intact and dehusked seeds during the development and maturation of seeds of indica and japonica rice. The triphasic pattern consisted of: (a) an initial phase, during which germination was stimulated by dehusking both in indica and japonica rice; (b) a second phase during which almost no dehusked seeds of indica or japonica rice germinated; and (c) a third phase during which intrinsic differences between indica and japonica rice were observed, with dehusking stimulating germination of indica rice but inhibiting that of japonica. Temperature regimes did not affect this triphasic pattern, but the time from the day of anthesis to mass maturity was affected by temperature regimes, and the effect was more pronounced in indica than in japonica rice.     

Plant Regeneration from Isolated Microspore of Indica Rice

Isolated microspores of rice (Oryza saliva L.) cultivars, IR36and IR43, belonging to the recalcitrant indica subspecies werecultured. Two types of microspores were observed after isolationfrom the fresh anthers and from pre-cultured anthers—onetype consisted of vacuolated, larger-sized grains, while theother was composed of microspores of smaller sizes with densecytoplasm. Within few days in culture, all the smaller sizedgrains were dead, and only the large grains were viable andproduced pollen embryos. After 30 days from culture, microcalliwere transferred to semisolid modified Murashige and Skoog mediumcontaining 1 mg/liter each of kinetin and naphthaleneaceticacid and kept under continuous light at 25?C. IR36 showed onlycell division while IR43 gave 32 green plants from these experiments. (Received January 18, 1990; Accepted July 4, 1990)     

籼粳稻杂交衍生RIL系的苗期抗旱性评价

为鉴定籼粳稻杂交衍生系的苗期抗旱性,以课题组自育的高代抗逆品系ZD15为母本、籼稻品种IR29为父本,以及杂交衍生的重组自交系群体120份为试验材料,利用PEG-6000对各材料苗期进行干旱胁迫处理,测定根长、根冠比、地上部鲜重、地下部鲜重、地上部干重和地下部干重;利用PEG-6000对各材料芽期进行干旱胁迫处理,测定芽鞘长和芽长。采用主成分分析和隶属函数法对各材料的抗旱性进行综合评价,根据综合抗旱D值可将122份材料分成3类,D值在0.201～0.400之间的有33份,属于不抗旱材料;D值在0.401～0.600之间的有79份,属于中等抗旱材料;D值在0.601～0.800之间的有10份,属于抗旱材料。利用D值进行逐步回归分析,结果表明根长、根冠比、地上部鲜重、地下部鲜重、地上部干重、地下部干重、芽鞘长和芽长8个性状均可作为水稻苗期抗旱性的评价指标。本研究筛选出的抗旱材料,可作为育种中间材料进一步培育,或作为育种资源加以利用,以丰富本区水稻育种的资源库。     

The Presence of an Abscisic Acid like Factor in Nonviable Rice Seeds

Experiments were carried out with viable and nonviable rice seeds to detect the nature of germination inhibitors. An abscisic acid like factor is present in nonviable seeds but absent in viable ones. The main source of the factor is the embryo although measurable amounts are also obtained from the husk; it is not found in the endosperm however. Interaction with GA₃ and IAA suggests that both the rice seed inhibitor and abscisic acid are antagonistic to GA₃ and partially reversed the IAA induced growth. The similarity of the UV absorption spectra of the inhibitor and abscisic acid also proves its presence in nonviable seeds. The inhibitor suppresses the α-anivlase activity both in intact and excised seeds in the same way as abscisic acid but the suppression is partially overcome with higher concentrations of GA₃.     

Purification of Debranching Enzyme from Mature Rice Seeds

Two indole alkaloids which induce the Epstein-Barr virus early antigen of Raji cells (B lymphocyte) were found in the cultured broth of Actinomycetes NA34-17, from which teleocidin B was also obtained. The active compounds isolated were identified from their spectral data and chemical evidence as (—)-indolactam V and (—)-14-O-acetyl indolactam V.     

植酸对杂交水稻V20B种子萌发及生理特性的影响

以杂交水稻V20B 为材料,研究外源植酸对种子萌发的影响。结果表明,外源植酸浓度为10 mmol/L 时能明显抑制种子萌发。生理生化检测表明,植酸对杂交水稻种子萌发过程中α-淀粉酶活性、可溶性糖和内源植酸含量变化有不同程度的影响。     

GABA Analogues Derived from 4-Aminocyclopent-1-enecarboxylic Acid

The incorporation of extra binding groups onto known ligands is a powerful tool for the development of more potent and selective agents at target sites such as the GABA receptors. In the present work we have attempted to build on the activity of the know potent GABA_A agonist 4-ACP-3-CA and its cis and trans saturated analogues CACP and TACP. We have investigated reactions to add thiol substituents to the α,β-unsaturated system of 4-ACP-3-CA. The reaction was successful with a limited number of thiols but gave products of mixed stereochemistry. The resultant thioether amino acids were screened for activity at human recombinant α₁β₂ γ_2L GABA_A receptors. The most interesting derivative was the benzylthioether which acted as an antagonist with an IC₅₀ of 42 μM for the inhibition of a GABA EC₅₀ dose (50 μM). This study has shown that GABA analogues derived by thiol addition to 4-aminocyclopent-1-enecarboxylic acid display interesting antagonist activity at the α₁β₂γ_2L GABA_A receptor. Special issue article in honour of Dr. Graham Johnston.     

籼、粳杂种的“随体丢失”

1985—1986,观察籼、梗及籼、粳Fl杂种终变期核仁染色体数,籼为2个二价核仁染色体,粳为1个二价核仁染色体,籼、粳Fl杂种核仁染色体数与父本水稻的核仁染色体数相同。由此,讨论了“随体丢失”在水稻育种,粳稻起源及遗传学方而的意义。     

Synthesis of Analogues of Ribosylbarbituric Acid

Abstract

Syntheses of 5-alkyl (5 b, c), 2′-deoxyribosyl (9, 10) and arabinofuranosyl (13) analogues of ribosylbarbituric acid (5a) are described. The compounds were prepared by condensation of persilylated barbituric acids with pentofuranosyl moieties. The 2′-tolylthio analogue (16) was obtained by an alternative procedure involving ring-opening of 6,2′-O-cyclouridine (15).     

次适温下水杨酸浸种对水稻种子萌发的效应

水稻种子于15℃以下0．01－5．0mmol.L^-1水杨酸浸种24h后,置于25,20和15℃下萌发,萌发后种子极和芽生长受到的影响不同,以15℃下萌发受到的促进作用最好,其效应随水杨酸浓度的增加而增加。     

Changes in Nicotinic Acid Content and Its Nucleotide Derivatives of Rice and Wheat Seeds during Germination

Relative distribution of bound and free forms of nicotinic acid in rice and wheat seeds and their metabolism during germination were the subject of the present investigation. Measurement of the levels of NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate) formed another part of the work. Total nicotinic acid in both rice and wheat increased with germination and was maximum at 72 hours. From this time onwards, it began to decline rapidly and at the end of experiment, i.e., after 120 hours, it was lower than that for ungerminated seeds on per seedling basis, although it was slightly higher on per g dry weight basis. Ungerminated seeds of wheat and rice contained about 89 per cent and 80 per cent respectively of their total nicotinic acid in bound form which became partially free in course of germination. Total nucleotides (oxidised plus reduced forms) increased progressively up to 96 hours followed by a slight fall at 120 hours. NAD reached a maximum at 24 hours and fell gradually thereafter. The depletion of NAD was associated with a progressive accumulation of NADH. NADP decreased from the peak value at 72 hours. Formation of NADP and its maintenance at high level depend on NAD in the oxidised form and the content slowed down in tissues with higher NADU/NAD ratio. A relatively large amount of NADPH was present throughout the experiment.     

The Effects of Ethanol on the Germination of Seeds of Japonica and Indica Rice (Oryza sativa L.) under Anaerobic and Aerobic Conditions

An examination was made of the effects of ethanol at 0.2–6.0%(v/v) on the germination, under aerobic conditions, of intactand dehusked seeds of indica rice (cv. Assam IV), which hadbeen harvested 14, 21 and 28 d after anthesis, and of the japonicarice (cv. Sasanishiki), which had been harvested 30 and 60 dafter anthesis. The inhibition of germination caused by dehuskingjaponica rice was overcome by 0.5–5% ethanol, with maximumgermination (frequently 100%) achieved at 3–5% (30 d afteranthesis) or 1–4.5% (60 d after anthesis) ethanol. Furtherincreases in the ethanol concentration reduced germination.The germination of dehusked indica rice was slightly inhibitedat 0.5 and 1% ethanol, whilst the promotion of germination by2% ethanol increased as the seeds matured. At all harvests germinationwas greatest at 3% ethanol, and at 5–6% ethanol germinationfell to 0%. Inhibition, no effect, or minimal stimulation ofthe germination of intact seeds of both japonica and indicarice by ethanol was observed at the concentrations examined.The absence of oxygen stimulated germination of dehusked japonicarice, but this germination was inhibited by ethanol. In contrastethanol had little or no effect on the failure of dehusked indicaseeds to germinate in anaerobic conditions. Thus ethanol treatmentmay help break the strong dormancy of dehusked seeds of indicaand japonica rice. The possible role of ethanol in stimulatinggermination in rice is discussed. Rice; Oryza sativa L.; seed germination; dehusking treatment; ethanol; indica; japonica; oxygen; dormancy; germination inhibition; seed formation     

籼稻体细胞培养再生植株染色体变异的研究

以IR36及IR54等品种的成熟种子及幼穗为外植体,获得籼稻体细胞培养再分化植株,并研究了再生植株当代(即第一代,SC_1)的染色体变异。在319株SC_1植株中发现四倍体10株,占总数的3.1％。在二倍体中发现不育株7株(占2.2％),其中经细胞学分析发现2株(1984及1985年各发现1株)为多染色体相互易位杂合子。减数分裂的研究表明,MRT植株终变期时染色体构形呈十分复杂的情况。除正常的12 Ⅱ外,还呈现出一系列的多价体。配对最高价性为拾价体,7 Ⅱ+1Ⅹ的构形占各种染色体构形总数的50.7％,分布最多。在这类染色体构形中,拾价染色体或呈环形(以7 Ⅱ+1⑩表示),或呈链形(以7 Ⅱ+1(?)表示)。这表明该植株12对染色体中有5条非同源染色体发生了相互易位,而这两株植株正是这种染色体易位的杂合子。     

几种影响籼稻成熟胚愈伤组织诱导及再生的因素

建立了适合5个籼稻品种成熟胚籼稻遗传转化的高效植株再生体系.N6基本培养基有利于籼稻愈伤组织的诱导和继代培养;N6大量元素和MS微量元素有利于愈伤组织的分化.降低分化培养基中蔗糖含量,加入适量山梨醇、Cu2 、Ag 和玉米素(2T)均可明显提高水稻愈伤组织的再生植株频率,5个品种分化频率均达到75%以上.