Chromosomal location of fertility restoring genes for ‘wild abortive’ cytoplasmic male sterility using primary trisomics in rice

Summary Identification and location of fertility restoring genes facilitates their deployment in a hybrid breeding program involving cytoplasmic male sterility (CMS) system. The study aimed to locate fertility restorer genes of CMSWA system on specific chromosomes of rice using primary trisomics of IR36 (restorer), CMS (IR58025A) and maintainer (IR58025B) lines. Primary trisomic series (Triplo 1 to 12) was crossed as maternal parent with the maintainer line IR58025B. The selected trisomic and disomic F₁ plants were testcrossed as male parents with the CMS line IR58025A. Plants in testcross families derived from disomic F₁ plants (Group I crosses) were all diploid; however, in the testcross families derived from trisomic F₁ plants (Group II crosses), some trisomic plants were observed. Diploid plants in all testcross families were analyzed for pollen fertility using 1% IKI stain. All testeross families from Group I crosses segregated in the ratio of 2 fertile: 1 partially fertile+partially sterile: 1 sterile plants indicating that fertility restoration was controlled by two independent dominant genes: one of the genes was stronger than the other. Testcross families from Group II crosses segregated in 2 fertile: 1 partially fertile+ partially sterile: 1 sterile plants in crosses involving Triplo 1, 4, 5, 6, 8, 9, 11 and 12, but families involving triplo 7 and triplo 10 showed significantly higher X² values, indicating that the two fertility restorer genes were located on chromosome 7 and 10. Stronger restorer gene (Rf-WA-1) was located on chromosome 7 and weaker restorer gene (Rf-WA-2) was located on chromosome 10. These findings should facilitate tagging of these genes with molecular markers with the ultimate aim to practice marker-aided selection for fertility restoration ability.     

Effect of acidic deposition on hybrid poplar- primary or predisposing stress?

Our research examined the role of acidic deposition as a primary, or predisposing, stress on 8–12 week old cuttings of hybrid poplar (Populos deltoides x nigra). Firstly, we examined the role of acidic deposition as a primary stress in terms of physiological indicators (gas exchange, chlorophyll concentrations, chlorophyll-a fluorescence). Our results suggest that levels of acid precipitation of > pH 3.5 did not act as a primary stress. Secondly, we hypothesized that acidic deposition could act by making trees more susceptible to drought. An acid treatment exposure regime was followed by 3–4 days of drought stress in a controlled environment. Preexposure to acidic deposition did not increase the degree, or rate of appearance, of water stress as indicated by predawn xylem pressure potentials and leaf conductances. Examination of cuticular water loss from excised leaves suggested that this parameter was insensitive to acidic deposition from pH 3.0 to 5.5.     

大花天竺葵组织培养初探

以‘亚里士多德’系列的大花天竺葵新品种的叶、叶柄和带芽茎段为外植体,进行了不定芽、愈伤组织的诱导及芽萌发的研究。结果表明,大花天竺葵叶片诱导不定芽分化的最适培养基为MS＋0.5 mg·L^-1NAA＋3.0·L^-16-BA,诱导率75.61%,平均不定芽个数4.98;叶柄诱导愈伤组织的最适培养基为MS＋0.3·L^-1NAA＋1.0·L^-16-BA,诱导率47.2%;带芽茎段诱导不定芽的最适培养基为MS＋0.5·L^-1NAA＋1.0·L^-16-BA,诱导率81.27%。     

益生菌PSB0201对原代培养罗非鱼肠道上皮细胞的影响

通过分离和原代培养尼罗罗非鱼肠道上皮细胞，并以其为细胞模型，研究目前已广泛用作益生菌的光合细菌PSB0201对其形态、增殖、存活率、通透性、胞浆游离Ca2＋和磷脂酶A2活性的影响。结果表明，与对照组相比，添加一定浓度的光合细菌PSB0201对肠道上皮细胞的形态和各生化指标均有一定影响，但是差异均不显著（P > 0.01）。表明在一定时间内PSB0201对尼罗罗非鱼肠道上皮细胞没有毒害作用，为其作为益生菌安全性的重新评价以及在包括水产养殖在内的农业中的应用提供了新的思路和一定的理论依据。     

基于植被降水利用效率的荒漠化遥感评价方法

 在考虑荒漠化评价的空间尺度和基准以及潜在评价指标的尺度特征的基础上,以国内外对土地荒漠化过程中植被降水利用效率(RUE)变化的研究为依据,提出一种以植被的降水利用效率为主要评价指标、适合于荒漠化遥感监测应用的荒漠化评价方法。该方法可很大程度上克服以植被指标为主的评价方法受降水波动影响大的缺点。这种方法重视不同荒漠化类型的共性特征,适合在多种类型荒漠化遥感评价中应用。     

贵州金丝桃组培快速繁育技术研究

为了建立贵州金丝桃快繁再生体系,对贵州金丝桃进行了组织培养研究.结果表明:茎段为贵州金丝桃组织最适外植体,初代培养最适宜芽诱导的培养基配方为1/4 MS+TDZ0.5 mg/L+ NAA0.01 mg/L;芽继代增殖最适宜的培养基配方为1/4 MS+ ZT 1.5 mg/L+ NAA 1.0 mg/L;最适宜壮苗生根的培养基为1/4 MS+ ZT 0.1 mg/L+ NAA 1.0 mg/L.     

Investigation into the population growth and its implications for primary schooling in Timor‐Leste by 2020

The nation‐building process of Timor‐Leste, the newest nation in Asia, faces significant demographic challenges due to its high population growth, which is the fastest in Asia. The major contributor for this unprecedented growth is the extremely high total fertility rate of Timor‐Leste, among the highest in the world. It is of great concern that if the current fertility rate and its implied population growth continue the population of Timor‐Leste will double in 17 years. The analysis in this paper clearly shows that the current extremely high dependency ratio will decline only marginally in the next 10 years and this will put tremendous pressure on the government to constantly keep up with the increasing number of children entering school every year. However, as the intrinsic value of human resource development feeds back into the overall society and economy, an adequate public investment in knowledge‐producing services at the earliest stages of life and throughout that life has the potential to change the demographic concern of Timor‐Leste into a future demographic dividend.     

卷柏启动培养研究

以卷柏（Selaginella tamariscina）幼叶、茎尖及茎段为外植体,研究了不同消毒方式的消毒效果以及基本培养基类型和激素组合对初代培养的影响。结果表明：以卷柏的茎尖为外植体,用5 g.L-1多菌灵处理8 h的消毒方式,取得了较好的消毒效果,无菌率可达79.8%;茎尖最佳初代培养基为MS＋KT 2 mg.L-1＋NAA0.2 mg.L-1＋IAA 0.1 mg.L-1。     

植物硼效率差异的研究进展

综述了植物种类及不同品种间，特别是甘蓝型油菜品种间硼效率差异的生理生化机理及遗传学和分子生物学研究进展。指出，植物细胞壁果胶含量的形态及光合初产物的种类和运输形式是导致植物营养生长硼效率差异的主要原因，但是否是生殖生长硼效率差异的原因有待进一步证实 。植物硼效率是由基因控制的，应用遗传学和分子生物学技术可得到理想的硼高效品种。     

烟草野火病菌初侵染源的研究

为探明烟草野火病菌的初侵染源，应用SPA－ELISA，间接－ELISA反应试剂盒对从田间及温室中采集的土壤、烟株根围、田间杂草、种子等进行了检测，明确云南烟草野火病的初侵染源主要为种子和根部残体。