Factors influencing fruit size in the strawberry (Fragaria ananassa Duch.)

Summary Fruit size is one of the most important characteristics of highly productive strawberry cultivars. The aim of the experiments was to establish the factors responsible for the expression of this trait. The total yield of large fruits correlates closely with the total yield of all fruits and depends mainly on the mean fruit weight of all fruits. The position of fruits on the inflorescence influences the decline of fruit size to a larger extent in small-fruited clones than in the large-fruited ones. The size of the fruit is controlled by the dimension of the receptacle and number of achenes. The stimulating effects of achenes are quite different in various genotypes and the fruit weight per achene declines with the inferior blossom position. The large-fruited clones have bigger leaves, a larger photosynthetic area, and thicker petioles and flower stalks. Their cells are larger, which is common for the giant genotypes. The results suggest that there exists a possibility for indirect selection of fruit size on the basis of some additional parameters, which can be useful particularily in the years of unsuitable weather conditions.     

Conservation of Pteropus livingstonii based on roost site habitat characteristics on Anjouan and Moheli, Comoros islands

Livingstone's fruit bats, Pteropus livingstonii, (Pteropodidae: Chiroptera) are endemic to only two islands, Moheli and Anjouan of the Comoros Islands in the West Indian Ocean. With an estimated population of less than 2000 individuals, P. livingstonii is listed as Critically Endangered on the International Union for the Conservation of Nature's Red List. Yet the habitat characteristics of these giant fruit bats, or flying foxes, are poorly known. I conducted field research during 5 months in 1998 focused on finding new roost sites, measuring characteristics of both roost sites and roost trees at new as well as previously identified roost sites, and recording the same characteristics for a set of absence sites. I identified six new roost sites allowing me to measure the characteristics of 15 known roost sites and seven absence sites. The study spanned both dry and rainy seasons and I found a significant increase in the number of individuals at roost sites during the rainy season. Bat roost sites were associated with presence of water, southeast aspect, steep slopes, and presence of several native tree species. Roost habitat was characterized based on biotic, abiotic and human factors. This research on habitat characteristics is contributing to the development of a conservation action plan for the Livingstone's fruit bats. However, further research on dry season roost sites and distribution as well as feeding sites is necessary in order to better understand their seasonal habitat requirements and therefore ensure the conservation of P. livingstonii.     

钙、钙调素在刺梨果实发育过程中的含量变化研究

为探讨Ca2 、CaM在刺梨果实发育过程中的含量变化,以贵农5号优系为试材,测定其果实发育过程中Ca2 和CaM的含量及可溶性总糖、还原糖、维生素C的含量.结果表明:刺梨果实发育过程中,Ca2 含量前期高后期低,呈逐渐下降的趋势;CaM含量呈波动状态,在果实发育的中前期,与果实发育状况之间成相互响应的曲线变化;果实发育的后期,CaM含量处于较高的水平,与此期可溶性总糖、还原糖、维生素C的高水平相对应.本文还对Ca2 、CaM在刺梨果实发育的不同阶段可能的调控机理进行了讨论.     

基于果实品质与EST-SSR标记的刺梨居群遗传多样性分析及核心种质构建

通过分析评价野生刺梨(Rosa roxburghii Tratt.)资源居群遗传多样性和遗传结构,同时构建核心种质,为刺梨资源的保护和发掘利用提供科学依据。本研究利用10对EST-SSR引物和9个果实品质性状指标对收集的12个刺梨自然居群(共102份种质)的遗传多样性及遗传结构进行分析,同时结合原贵州省32份初级核心种质,采用位点优先取样策略进一步构建西南地区核心种质。结果表明,黔西(QX)居群拥有最高的Shannon信息指数I=0.6965,基因多样性指数h=0.3935,多态位点百分率p=84.62%;而古丈(GZ)居群则无论在分子数据还是表型数据都表现为遗传多样性最低;AMOVA分析表明刺梨居群内遗传变异在87%以上,居群间基因流Nem在3.5以上、平均Nei’s遗传距离(GD)0.223。构建的19份核心种质等位基因保留率和稀有等位基因保留率均为100%,能够代表原种质的遗传多样性。西南地区野生刺梨的遗传变异主要发生在居群内,居群间具有基因交流频繁、Nei’s遗传距离小等特点,构建的19份核心种质从等位基因保留率、稀有等位基因保留率及地理分布均能够较好地代表原种质的遗传多样性。自然居群以黔西(QX)居群遗传多样性最高。因此,野生刺梨的保护策略可采用就地保护黔西(QX)居群与迁地保护19份核心种质相结合的方法进行。     

3个杏品种果实香气顶空固相微萃取气质联用分析

对三个杏品种“金太阳”、“鲁杏1号”、“鲁杏2号”成熟期果实顶空微萃取果肉中的挥发性物质进行气相色谱—质谱分析鉴定。金太阳杏检测出33种香气成分,占总峰面积的82.37%,主要香气物质为乙酸己酯、乙酸－4－己烯－1－酯、二羟乙酸、6－甲基－5－烯基－2－庚酮;“鲁杏1号”检测出10种香气成分,占总峰面积的51.18%,主要香气物质为二羟乙酸、苯乙醇、二乙基邻苯二甲酸酯、2-苯并噻吩;“鲁杏2号”检出10种香气成分,占总峰面积的48.06%。主要香气物质为乙醇、乙酸己酯、顺-3-己烯基-乙酸酯。三个品种间香气成分和含量均存在差异,杏香气成分是杏选育评价标准的重要指标之一。     

Ten consecutive years of regulated deficit irrigation probe the sustainability and profitability of this water saving strategy in loquat

The successful application of postharvest regulated deficit irrigation (RDI) over ten consecutive years (from season 1999/2000 to season 2007/2008) confirms the sustainability of this strategy for producing ‘Algerie’ loquat. Postharvest RDI consisting in a reduction of watering (between 45 and 80% depending on the season) from early June until the end of August, improved loquat profitability by increasing fruit value and by reducing water consumption with respect to fully irrigated trees (control). The increase in fruit value in RDI trees was due to a consistent improvement in harvest earliness as a result of an earlier blooming. Water savings of around 20% did not diminish yield nor fruit quality. Water use efficiency in RDI trees rose by over 30%. Water productivity reached 9.5 € m⁻³ of water applied in RDI trees versus 6.6 € m⁻³ in control trees. The most noticeable effect of RDI on vegetative growth was a significant and progressive decline in trunk growth. The canopy volume seems to be strongly influenced by pruning and no significant effects were detected in this parameter. Our results confirm the suitability of RDI in loquat and the economic benefits of saving water during the summer.     

融合多源图像信息的果实识别方法

光线变化与目标重叠是影响自然环境中果实正确识别的重要原因。为了降低两者的影响,研究了融合多源图像信息的果实识别方法。在图像配准的基础上,优选了H分量图与幅度图像作为待融合的源图像;由模糊推理系统(隶属度函数和模糊规则)决定权重,采用加权平均策略实现图像的像素级融合;根据融合图像中果实区域的分布规律,设计了一种基于直方图的首阈检测法以获得最佳的果实分割效果;利用深度图像的统计特性,设计了一种逐层分割图像的方法以解决重叠果实的分离问题。实验结果表明:多源融合图像用于果实识别与定位比单一图像具有更好的准确性与鲁棒性,对重叠果实的正确识别率在83.67%~94.22%之间。     

柑橘类果汁中柚皮苷的分析

柚皮苷是柑橘汁中主要的苦味物质之一,其含量高低影响果汁的色泽、口味、稳定性等.通过分光光度法分析了9种柑橘类果汁中柚皮苷的含量,研究结果表明：胡柚汁中柚皮苷含量最高,为3.018 g/L,芦柑汁中柚皮苷含量最低,为0.310 g/L.在此基础上,用数学统计的方法对9种柑橘类果汁中柚皮苷含量差异性分析表明：脐橙汁与象山橘汁,椪柑汁与蜜柚汁柚皮苷含量无差别;椪柑汁比芦柑汁高,蜜柚汁比芦柑汁高,差异显著;其余种类果汁间柚皮苷含量均有极显著差异.     

1-MCP对杏果实采后贮藏品质的影响

以凯特杏果实为试验材料,研究了1甲基环丙烯(1MCP)对果实采后贮藏品质特性的影响。结果表明:使用1.0μL/L1MCP处理杏果实后,可以显著地降低乙烯释放速率和呼吸速率,显著地抑制叶绿素的降解和类胡萝卜素的增加,促进类黄酮和总酚的积累,延缓果实抗坏血酸含量和硬度的下降,但对可滴定酸和可溶性固形物含量无明显效果。     

臭氧果蔬保鲜包装技术及试验

臭氧果蔬保鲜技术的关键是如何控制和调节包装内氧气和二氧化碳的体积分数,包装材料气透率是调节包装内气体体积分数的主要因素。综合果蔬呼吸和薄膜透气两个相互交叉的动态过程,提出一种新的果蔬包装薄膜透气率的计算方法。在清水蜜桃、油豆角的臭氧保鲜试验中测试了臭氧果蔬保鲜薄膜不同厚度以及不同保鲜时间的腐烂率、好果率、失重率、可溶性固形物含量、还原糖含量、总酸、维生素C含量、叶绿素含量等指标,结果表明,以上果蔬的保鲜期至少延长2周以上。