南德温种公牛原精、冻精品质初步分析

本文通过统计 1 999年～ 2 0 0 2年 4年中南德温种公牛采精记录 ,对采精量、原精密度、原精活力以及冻后活力进行初步的总结 ,并就这 4项内容的数据进行各季节及各年的相互比较分析。通过数据分析 ,初步总结出了南德温这一引进的新品种鲜精和冻精的品质特性。不同的年份和季节对南德温牛精液无明显影响     

红肉火龙果与白肉火龙果花特性比较

本试验通过红肉火龙果和白肉火龙果花的外形、花粉粒大小和生活力的差异比较,探究红肉火龙果授粉结实率低的原因。结果表明,白肉花柱比红肉花柱约长1cm。白肉的花筒部分弯曲,使柱头能接触到雄蕊;而红肉火龙果柱头明显高于雄蕊,因此自花授粉率低。红肉火龙果花粉粒较白肉火龙果小。随贮藏时间延长（48h内）,火龙果花粉生活力逐渐下降。贮藏12h后,红肉火龙果的花粉生活力比白肉火龙果低8.5%。     

不同叶鞘色玉米单倍体花粉活力差异研究

针对玉米紫色叶鞘自交系×绿色叶鞘DH系的8份F1材料,经杂交诱导、海南自然加倍自交结实收获607份DH系,就紫色叶鞘和绿色叶鞘DH系数量、污染率、平均污染株数及绿色叶鞘DH系受紫色叶鞘、绿色叶鞘污染株数进行适合性检验和分析.结果表明,紫色叶鞘单倍体花粉活力强于绿色叶鞘单倍体.     

Modelling the population viability of a threatened amphibian with a fast life‐history

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Effects of variable egg incubation temperatures on the embryonic development in Arctic charr Salvelinus alpinus

An evaluation of different thermal regimes during incubation of Arctic charr Salvelinus alpinus L. egg was conducted with regard to embryo survival and development. The study consisted of two major parts: In experiment A, a range of commonly used thermal regimes, constant and variable ranging from 2.7°C to 7°C, were tested for differences in embryo survival and developmental status of newly hatched alevins. Experiment B assessed the timing of a shift from autumn (6°C) to winter temperature (2.5°C) and its effect on embryo survival and the occurrence of spinal deformities in newly hatched alevins. In general, incubations that were initiated at temperatures below 3°C resulted in significantly higher mortality rates and spinal deformity frequencies than other treatments. Hence, Arctic charr eggs require an initial warmer period for unimpaired embryonic development. A general negative correlation was found between the duration of this warmer period (6°C) and both mortality rates and frequency of spinal deformities. The total absence of the 6°C period had the most detrimental effect, with deformity frequencies at least four times higher than all treatments with an initial warmer period. The upper incubation temperature threshold was not reached in the study. The highest temperature tested (7°C) did not result in excess mortality or increased deformity frequency. Higher incubation temperature resulted in less developed alevins at hatching, i.e. alevins were smaller with more yolk remaining. However, measurements on alevins from incubations at variable temperatures revealed different temperature effects on growth and yolk consumption during different parts of embryonic development.     

四倍体神农香菊与露地菊‘纽9717’种间杂交初步研究

以四倍体神农香菊(Dendranthema indicum var.aromaticum)和露地菊‘纽9717’(Dendranthema×gandiflorum‘niu9717’)为试材,对其进行花粉和柱头的微观形态观察、最适花粉萌发的培养基筛选,同时测定花粉活力和柱头可授性及不同授粉方式下的结实情况,并对杂交获得的F1代植株性状进行表型分析。结果表明:四倍体神农香菊和露地菊‘纽9717’均为单粒花粉,有3个萌发沟,柱头均在丫状期开始授粉,最适花粉萌发的培养基均为ME3+150g/L PEG4000+150 g/L蔗糖+0.1 g/L硼酸+0.1 g/L Ca~(2+);四倍体神农香菊在开花第4天花粉活力最高,为64.63%,在13:00花粉活力最高,为54.56%,在开花第9天13:00—14:00时柱头可授性最强;露地菊‘纽9717’在开花第6天时花粉活力最高,为11.63%,在13:00花粉活力最高,为9.26%,在开花4~5 d 12:00—13:00时柱头可授性最强;不同授粉方式的结果显示,四倍体神农香菊与露地菊‘纽9717’杂交在去雄、套袋、人工异花授粉条件下结实率最高(79.28%);杂交后获得的F1代21株植株,在植株形态、叶片和花蕾方面表现出不同的性状,其中2株呈匍匐状生长,8株表现为叶长≤叶宽,7株叶缘锯齿为圆钝,10株现蕾早,且大多数花蕾为黑褐色,仅1株的花蕾为绿色。     

贮藏温度对向日葵花粉生活力的影响

为了解决向日葵杂交育种中花期不遇或远距离杂交等问题,探寻适合向日葵花粉长期贮藏的条件,以3个向日葵品种的花粉为试材,均在室温(20℃)、低温(4℃)、冷冻(液氮处理后-80℃保存)、超低温(-196℃的液氮中保存)4种温度条件下保存360 d,采用离体培养的方法,定期测定了不同贮藏时间后的花粉活力,以探索适宜向日葵花粉贮藏的温度条件。结果表明:20℃室温贮藏,花粉活力下降很快,贮藏1 d后花粉活力降至50%以下,第7 d时已基本失活,不适宜花粉贮藏;4℃低温贮藏,第10 d时花粉活力维持在50%以上,超过10 d后花粉活力快速下降,适宜花粉10 d内的短期贮藏;-80℃冷冻和-196℃超低温贮藏,至360 d时花粉活力与贮藏前相比均变化不大,适宜向日葵花粉的长期贮藏。     

Relative importance of chinook salmon abundance on resident killer whale population growth and viability

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Spray pollination as a labor-saving pollination system in Japanese pear (Pyrus pyrifolia (Burm.f.) Nakai): Development of the suspension medium

Effects of suspension media used for spray pollination on pollen grain viability were investigated in Japanese pear (Pyrus pyrifolia (Burm.f.) Nakai ‘Kosui’). The suspension media tested in this study consisted of pectin methylesterase (PME) and polygalacturonase (PG) combined with either 0.1% agar or 0.04% xanthangum (XG). We also evaluated the influences of spray pollination on fruit set and fruit quality. Pollen grain viability, as measured by germination and pollen tube growth rates, was maintained in media supplemented with 0.1 mg L⁻¹ PME or 0.1 mg L⁻¹ PG. The level of fruit set after spray pollination using media containing PME or PG in combination with either 0.1% agar or 0.04% XG was almost the same as the level after artificial pollination by hand (hand pollination). The media containing XG combined with either PME or PG seemed to show better results for pollen grain viability and fruit set, although the results were variable from year to year. With regard to fruit size, shape and other parameters for fruit quality, spray pollination and hand pollination gave comparable results, irrespective of the medium composition. The time required for spray pollination was less than half of that required for hand pollination, and the amount of pollen grain required for spray pollination was one-third or less than the amount required for hand pollination. Thus, spray pollination may be a time- and labor-saving pollination system for the cultivation of Japanese pear.     

平阴玫瑰花粉生活力及其贮藏条件的研究

 对22个平阴玫瑰品种的花粉进行了生活力测定及贮藏性能研究。结果表明, 不同玫瑰品种以及在不同贮藏条件下的花粉生活力和耐贮藏能力不同。采收当日‘紫枝玫瑰’的花粉萌发率最高(90.0% ) , ‘朱紫双辉’花粉萌发率最低(9.5% ) ; 花粉适宜贮藏条件为干燥、低温环境。花粉生活力随着贮藏时间的延长而下降, 5月份室内自然温湿度条件下贮藏的花粉生活力下降较快, 30 d后绝大多数品种花粉活力降为零; 冻藏( - 4～- 6 ℃) 的花粉生活力下降较慢, 60 d后仍然保持较高的萌发率, 一年后多数品种仍有一定的生活力。