Rain effect on pollen–stigma adhesion and fertilization in almond

The fact that rainy weather negatively affects production in almond is well-known by growers. However, as far as we know, no previous study has been carried out in this species to determine if the rain is able to wash off pollen grains from the stigma surface and consequently affect fertilization efficiency. To answer this question, flowers of the self-compatible almond cultivar ‘Antoñeta’ were emasculated on branches of trees in the field, pollinated by hand with pollen of the cultivar ‘Marcona’, and sprayed with water to simulate the rain effect at 4, 8, 24 and 48 h after pollination. A control for which no treatment was applied was also included in the assay. Seven days after spraying the flowers, the number of germinated pollen grains on the stigma was recorded in 10 pistils for each treatment by fluorescent microscopic observation. In addition, for each treatment the initial and final fruit set were determined at 30 and 60 days after pollination, respectively. The following year additional assays were performed in the field and in the laboratory in order to complete the study with earlier treatment times. Thus, an assay of rain simulation in the field at 0 and 2 h, and other consisting on immersing a branch with flowers and shaking it in a water container in the laboratory at 0, 30, 60 and 120 min after pollination were performed. One sample more was immersed, shaken, then pollinated and again immersed and shaken. The results from field assays showed that adhesion of pollen grains to the stigma was very quick and strong, and the treatments did not significantly affect pollen–stigma adhesion and subsequent fruit set. On the other hand, laboratory results showed that all washing treatments decreased the number of germinated pollen grains on the stigma, mainly when the flowers were immersed before pollination. In conclusion, the results showed that the simulated rain was not able to completely wash off pollen grains from the stigma surface, although it seems to affect adhesion in forthcoming pollinations.     

硒对体外培养小鼠成骨细胞形态、增殖和活力的影响

本文旨在探讨不同浓度亚硒酸钠溶液对体外培养的小鼠成骨细胞的形态、增殖及活力的影响。以出生24h的昆明小鼠颅骨为材料,通过酶消化法来分离成骨细胞,并分别接种于不同浓度的亚硒酸钠培养液(0.00、0.05、0.1、0.2、0.4、0.6、0.75、1.0 mg/L)中,倒置显微镜下观察成骨细胞的形态变化,采用MTT法测定细胞增殖率,结晶紫染色法测定细胞活力。48 h内,浓度高于0.4 mg/L时亚硒酸钠抑制细胞增殖且降低细胞活力,而低于0.2mg/L时亚硒酸钠可促进细胞增殖,增强了细胞活力。结果显示硒对成骨细胞的增殖和活力呈双向调节,硒作用呈浓度剂量依赖性。     

植物花粉超低温保存研究进展

花粉保存是种质资源保存的方法之一,近年来花粉超低温保存研究在许多种植物上取得了进展.收集了近20年来国内进行超低温花粉保存研究的资料,对研究中的主要影响因素和遗传性变化进行了叙述.     

丁香花粉生命力及贮藏条件的研究

本试验以七种丁香为试材,分别进行了新鲜花粉生命力测定比较、不同贮藏条件对花粉生命力的影响以及不同种丁香花粉贮藏力的差异三方面的研究,旨在为解决丁香杂交育种的花期不遇或远距离杂交问题提供科学的依据,提高杂交的成功率。试验结果表明:红丁香的花粉生命力最高,可达81.5%,其次为蓝丁香和小叶丁香,白丁香最低;小叶丁香的花粉贮藏力最强,在低温条件下可以贮藏60天以上,其次为红丁香和蓝丁香;丁香花粉适宜的贮藏温度为0-2℃低温条件。图2表3参18。     

三种松树花粉的营养分析

油松，华山松，白皮松花粉的营养成分分析结果表明，３种松花粉中含有丰富的蛋白质、脂肪、糖、矿质元素和维生素等多种参与人体代谢的生理活性物质。其中５种人体不能合成的氨基酸含量较高，脂肪含量较低，而不饱和脂肪酸含量很高。依据营养成分分析结果，对３种松花粉的医药保健作用做了阐述。     

Community Forestry Enterprises in Mexico: Sustainability and Competitiveness

Community-based forest management, such as Community Forest Enterprises (CFEs), has the potential to generate positive socioenvironmental and economic outcomes. We performed a detailed survey of financial and production parameters for 30 of the approximately 992 CFEs in Mexico in order to estimate costs, income, profits, and sustainability of harvest levels for forest management, harvest, and sawmilling. Fourteen of the 30 CFEs harvested more timber than they grew in 2011, suggesting issues with sustainability, but only two of these had harvest far above annual growth, and five of those were only a fraction more than annual growth. All of the 30 CFEs except one made profits in forest management and timber growing. For timber harvesting, 22 of 30 CFEs made profits, but the losses were small for the other CFEs. For the 23 CFEs with sawmills, 18 made profits and five had losses; the greatest returns for the CFEs accrued to those with sawmills for lumber production. On average, the CFEs surveyed had high costs of production relative to other countries, but the CFEs were still profitable in national lumber markets. If Mexico were to begin importing large amounts of lumber from lower cost countries, this could pose a threat to CFE profitability.     

An overview of Ontario's Stock Quality Assessment Program

Since 1992, the Stock Quality Assessment Program at the Ontario Forest Research Institute (OFRI) has offered seedling physiological testing services to foresters and nursery managers. The purpose of this program is to improve nursery stock quality and plantation performance by developing and applying procedures for assessing the physiological quality of nursery stock. Two levels of testing are available: Seedling Certification and Problem Stock Testing. Testing at both levels involves a visual assessment, measurement of chlorophyll fluorescence of the foliage and root growth potential. Applying these tests has directly improved plantation establishment between 1992 and 1995 by preventing over 3 million damaged seedlings from being planted, at an estimated regeneration cost savings of over $2 million (Can). Consideration of cost-benefits for both direct and indirect values demonstrates the merits of a stock testing program. Testing has been conducted either at OFRI or at a private lab, providing clients with an impartial assessment of their stock. Consistent test results, comparable from year-to-year and between laboratories, are achieved by the use of controlled environment testing, trained personnel and duplicate testing on selected stocklots. A database comprised of physiological test information for over 1100 stocklots provides a basis for comparing and ranking seedlings grown throughout the province. This database may be used to refine operational nursery practices, to evaluate changes in seedling quality over time, and to relate seedling quality to field performance.     

五月季竹开花结实的研究

五月季竹Phyllostachys bambusoides Sieb et Zucc是我国广为分布的优良竹种。本文综合报导关于五月季竹花茅的发育和花期;花的生长;花粉的形态、生活力和发芽率及花粉的败育;自然授粉和结实等方面的研究结果。     

香水莲花花粉的采集、干燥和贮藏特性研究

【目的】研究香水莲花Nymphaea hybrid花粉活力和贮藏特性,以期为香水莲花有性繁殖和杂交育种的生产实践提供理论基础和技术指导。【方法】以黄、粉、紫3种不同花色的香水莲花品系为试材,采用花粉离体萌发培养基法测定不同开花天数(开花1、2、3、4、5 d)的香水莲花花粉活力、同一天不同时间段的香水莲花花粉活力、3个不同品系的香水莲花花粉活力、不同干燥方法(室内通风自然干燥、烘箱干燥和硅胶干燥)的香水莲花花粉活力及不同贮藏条件(室温、4、-20、-80℃)下贮藏不同时间(5、10、30、50、70、90、120、180 d)的香水莲花花粉活力。【结果】1)3种花色香水莲花的花粉活力均随开花时间呈现先升高后降低的变化规律,开花2 d的花粉活力最高;2)在一天7:30-17:30中,9:30-11:30的花粉活力较强;3)3个香水莲花品系间花粉活力存在差异,其中‘黄花型’香水莲花的花粉活力(60.61%)最高,‘紫花型’香水莲花的花粉活力(48.15%)最低;4)硅胶干燥法是香水莲花花粉干燥的最佳方式;5)4℃适于香水莲花花粉的短期贮藏,-20℃和-80℃适于香水莲花花粉的长期贮藏。【结论】在香水莲花开花2 d的9:30-11:30采集花粉,采用硅胶干燥法干燥后短期贮藏于4℃,长期贮藏于-20℃或-80℃条件下,可有效延长香水莲花花粉的寿命。     

柳树花粉生活力分析

花粉生活力是植物杂交育种成败的现柳树种间、杂种间及亲本与杂种之间的花粉生活力差异较大.用花粉生活力较高的绵毛柳P716做花粉贮藏实验,结果表明花粉生活力与贮藏时间呈负相关,低温干燥对花粉贮藏是有利的.