Bulk pollen pollination in maize for efficient construction of introgression populations with high genome coverage

Introgression populations consist of a set of introgression lines or families, constructed by continuous backcrossing to the recurrent parent, while carrying a limited number of chromosome segments from a donor parent in their genomes. Increasing the genome coverage is an important aim when constructing introgression population. In this study, we proposed bulk pollen pollination (BPP) method and used it to increase the genome coverage of a maize introgression population. The results showed that the genome coverage of the introgression population constructed using BPP method reached 100% at BC₃ generation, which accorded with the simulation result. The BPP‐based BC₃F_1:2 population could identify most quantitative trait loci (QTL) detected using the F_2:3 population, especially major QTL. Simulation analysis showed that the genome coverage of introgression population increased with the increase of population size and the number of bulked plants, and decreased with the increase of backcross generation. Our results proved the reliability of the BPP‐based introgression population in increasing genome coverage and detecting QTL, and provided references for constructing high‐coverage introgression populations.     

天目蜜李丰产技术研究

配置一定比例授粉树种，是提高授粉效果获得丰产的基础。授粉树比例幼龄期高于成龄期，授粉树花期应与天目蜜李基本一致、果形近似、品质好、抗性强的优良品种，这样才能确保果品的质量与产量。     

基于级联卷积神经网络的番茄花期识别检测方法

对作物花期状态的准确识别是温室作物执行授粉的前提。为提高花期状态识别的准确度，该研究以温室番茄为例提出了一种基于级联卷积神经网络的番茄花朵花期识别方法。首先采用改进的端到端的特征金字塔网络FS-FPN实现番茄花束的分割，然后采用Prim最小生成树对分割后的花束图片进行花期识别优先级排序，最后将已排序的分割花束图片输入改进的Yolov3网络，实现番茄花朵花期状态的精准识别。在由1600幅包含花蕾期、全开期、谢花期、初果期4类花期状态的番茄花束图像构成的数据集上，所提方法对番茄花朵花期平均检测时间为12.54 ms，平均检测精度分别比Mask R-CNN和SPP-Net提高了3.67%和2.39%，识别错误率比改进前的Yolov3网络降低了1.25%。最终将该方法部署到番茄授粉机器人上，并在大型玻璃温室内进行验证，结果表明，所提方法对番茄花朵各花期的检测精度分别为花蕾期85.71%、全开期95.46%、谢花期62.66%、初果期88.34%，该研究结果可为智能授粉机器人的精准作业提供重要依据。     

木棉雄蕊特征与其繁殖策略的关系分析

采用野外观察和实验室检测方法,对云南省个旧市冷墩村的木棉花部结构、雄蕊特征、花粉活性进行研究。结果表明,自然种群中花部形态特征具有一定变异性,3层雄蕊变异系数大小关系显著。在湿度为60%、温度为35℃时花粉活性最强。研究发现,木棉雄蕊长短变化可能有利于不同传粉生物传粉效率提高和增强适应性;木棉高层雄蕊花药个体大、花粉数量多、活性高,适应干热河谷传粉繁殖条件;温度较低时,底层花药花粉活力相对较高,可为逆境环境下木棉高层花药受损后提供后备花粉源。文章就木棉花部形态与繁殖关系、木棉形态及花粉活力对繁殖的影响进行讨论。     

梨不同品种授粉特性的研究

选用中梨一号、秋黄、八月酥、西子绿、丰水5个梨优良品种进行自花及异花授粉,研究其落花落果及坐果特性。结果表明,不同品种自花授粉的坐果率不一样,中梨一号、秋黄、八月酥自花授粉不结实,而丰水自花授粉的坐果率最高,为37.69%。不同授粉品种对落花落果和坐果率的影响也不同,坐果率与落花落果率呈极显著负相关,坐果率与花粉量呈显著正相关。     

Comparative morphology of the digestive system of 19 species of Southern African myomorph rodents in relation to diet and evolution

Trends in digestive system-morphology have been examined in 19 species of Southern African myomorph rodents. Structure was related to function, diet, and evolution. Characters related to an ancestral proteinaceous diet, and specialized characters associated with herbivory, were recognized. All stomachs were of the unilocular hemiglandular type with increasing degrees of cornification of the corpus, although the stomach of Saccostomus compestris approached the bilocular discoglandular condition. Those of Thallomys paedulcus and Mystromys albicaudatus were highly modified in containing numerous papillae in the corpus, possibly associated with gastric fermentation. The most complex caeca, of the herbivorous Otomyids, possessed numerous haustra and internal papillae probably associated with caecal microbial fermentation.     

中华蜜蜂对荔枝园常见化学农药的触角电位反应

利用触角电生理技术测定了中华蜜蜂对荔枝园常用10种化学农药的触角电位反应（EAG）。结果表明，中华蜜蜂对不同化学农药品种的EAG反应值各不相同，其中高效顺反氯氰菊酯引发的EAG反应值最大，而生绿Bt粉剂引发的EAG反应值最小，两者间的差异达到极显著水平。这些农药品种引发中华蜜蜂EAG反应值的大小顺序为：高效顺反氯氰菊酯〉乐斯本乳油〉乐果乳油〉杀虫双水剂〉农地乐〉敌杀死乳油〉阿维菌素乳油〉灭百可乳油〉敌百虫乳油〉生绿Bt粉剂。这些研究结果可为我们从保护授粉蜜蜂的角度出发，在荔枝园中有选择性地施用对蜜蜂不敏感的农药品种提供有益参考。     

Influence of self-pollination in fruit quality of autogamous almonds

Due to the several advantages expected from growing self-compatible almond cultivars, breeding programmes have recently introduced self-compatibility as an important trait. However, doubts have arisen regarding the capability of the newly obtained self-compatible almonds to produce good yields in monovarietal plantations, and the commercial quality of the fruits from self-pollination. For this reason, in the last years several studies have been conducted to evaluate fruit set and fruit traits following self- and cross-pollination of self-compatible almonds. Their results showed inconsistencies for fruit set and for some of the fruit traits studied. Thus, while some studies showed no differences between both pollination types for any of the fruit traits, others clearly showed important differences with the detriment of self-pollination for commercially important fruit traits. The fact that some of these studies evaluated a low number of individuals and/or fruit traits, implies the need of a more complete study. In this work, 10 fruit traits were studied in 26 self-compatible almonds following self-pollination by bagging and open pollination treatments. In general, and despite a few individuals showed differences between both pollination types for two of the traits, the results showed no influence of self-pollination in fruit quality.     

美国杏李人工投粉试验初报

美国杏李中一些品种自花授粉不结实，必须配置授粉树或进行人工辅助授粉。授粉方法，用2．5kg蔗糖＋0．15kg硼砂＋20g花粉＋50kg水配成溶液喷雾。各授粉品种组合、授粉效果从优到劣的排列顺序为：风味皇后♀×恐龙蛋♂、风味皇后♀×味厚♂风味皇后♀9×味王♂。     

不同保果方式对串番茄品种果穗整齐度及产量的影响

研究了花序电动振动辅助授粉、PCPA蘸花处理及自然授粉对串番茄ST 02、ST 03、ST 04的果穗整齐度和产量的影响。结果表明,电动振动辅助授粉和蘸花处理较自然授粉明显提高了果穗的整齐度和产量,且蘸花处理的产量最高,操作最为便捷。