Metabolie Engineering of Flower Color in Ornamental Plants

Abstract

Advances in the knowledge of plant pigment pathways at genetic, biochemical and molecular levels, and the establishment of genetic transformation methods for an increasing number of plant species have paved the way to genetic engineering of flower and plant color for ornamental purposes. From trial-and-error approaches based on the available few genes, the trend is now to comprehensively study the target species, genotypes and pigment pathways to precisely address specific breeding goals. This review examines the state of the art in this field, from the pioneering stages to fundamental and applied research on flavonoids, which is being extended to carotenoids and is also likely to involve other pigments in the near future.     

Citric acid extraction—An underestimated method in forest nutrition?

Since recent studies reveal citric acid to be favorable for estimating plant‐available P in soils, we investigated if it can also be used for assessing other nutrients. According to our results, it provides stronger correlations with the tree nutrition for Mg (beech, spruce), Ca+K (beech) and Fe (spruce) than the standard methods for determining exchangeable cations. Thus, when estimating plant‐available P by citric acid‐extraction, these cations should be additionally measured in ICP analysis.     

Seedling emergence,coleoptile length,and plant height relationships in crosses of dwarf and standard-height wheats

Summary Seedling emergence was closely correlated with coleoptile length and plant height among parents, F₂ and F₃, populations of crosses involving dwarf wheats Olesen Dwarf (CI 14497), Norin 10 derivative D6301, Tom Thumb derivative D6899, and the standard-height varieties Ramona 50 and Nainari 60. Genetic mechanisms that governed plant height also influenced coleoptile length, but the relative effects of genes showing dominant or epistatic effects appeared to be different. With respect to the two parents involved in each of 15 crosses, mean F₂ coleoptile lengths were consistently closer to the low parent value than were corresponding mean F₂ plant heights. A slight curvilinear relationship was also found between coleoptile length and plant height of F₃ lines. The results suggest that selection of semidwarf wheats with long coleoptiles and improved emergence properties from crosses involving the dwarf wheats of this study would be unlikely.     

不同电动植保无人机稻田雾滴沉积分布试验研究

为了研究旋翼类型和喷头类型对雾滴沉积影响,针对5种电动植保无人机进行水稻田雾滴沉积分布试验研究,试验机型包括单旋翼和多旋翼,喷头类型涉及离心式和液力式,并设置15L/hm2相同施药量,研究测定各机型的有效喷幅、雾滴沉积分布和冠层间的药液沉积量。试验结果表明:单旋翼机型具有较大的有效喷幅;离心式喷头雾滴沉积粒径较小,但雾滴沉积密度更大;各机型在作物上层的雾滴分布均匀性和药液沉积量最优,中层最差;相比液力式喷头,离心喷头可以获得更好的雾滴穿透效果。     

基于深度学习的马铃薯叶片病害检测方法#br# #br#

植物病害对食品安全具有灾难性的影响,它可以直接导致农作物的质量和产量显著下降,因此对植物病害的早期鉴定非常重要。传统的农作物病害诊断需要非常高的专业知识,不仅费时费力,还效率低下。针对这些问题,利用深度学习的方法,以马铃薯叶片为研究样本,基于TensorFlow开发Faster R-CNN网络模型。采用本地增强的方式对带有早疫病、晚疫病和健康的马铃薯叶片进行图像扩充,应用COCO初始权重进行迁移学习,探究了数据类别对模型检测结果的影响。结果表明,随着训练数据类别的增多模型性能会有略微的降低。同时还训练YOLOv3,YOLOv4网络与该模型进行对比,测试结果表明,所提出的Fater R-CNN模型优于其他网络模型。经检测该模型最佳精度达到99.5%,该研究为马铃薯病害检测提供了技术支持。     

公路草坪养护管理技术初探

为保证草坪绿化质量 ,延长其寿命 ,结合近年来在公路草坪施工与养护管理中积累的实践经验 ,对公路草坪的种类、生长习性 ,以及草坪建植后的浇水、除杂草、修剪、施肥、病虫害防治等养护管理技术进行了探讨与总结 ,以期为各地公路草坪绿化建设提供借鉴与参考。     

Influence of race and post infection temperature on two components of partial resistance to wheat leaf rust in seedlings of wheat

Summary Components of partial resistance, infection frequency and latency period, were determined in 71 winter and spring wheat genotypes in the seedling stage, after infection with three races of leaf rust (Felix 3B, Clement B and Betuwe 85C) at three different day/night temperature regimes (24/18°C, 18/12°C and 12/6°C). The genotypes were split into two groups and two separate experiments were carried out. Five genotypes, SVP 84039, Akabozu, Banco, BH 1146 and Orso, conferred a low infection frequency and a long latency period and Westphal 12A a long latency period, indicating a relatively high level of partial resistance. The correlation coefficient between infection frequency and latency period was low. Race-specificity was not found. There was a significant temperature effect on the latency period. In the second experiment the temperature x genotype interaction was significant. Temperature-response functions of transformed data demonstrated that the latency periods of four relatively resistant genotypes, Westphal 12A, Banco, BH 1146 and Orso and of Sarno and Mirela were most sensitive to temperature. The range between the genotypes with the longest and the shortest latency period was highest at 12°C. Therefore, low temperature regimes are preferred to distinguish differences in level of partial resistance.     

百色干热河谷地区降雨氢氧稳定同位素特征及芒果树水分来源研究

百色市右江河谷是我国著名的干热河谷之一,干旱是该地区最严重的气象灾害。芒果是该地区地理标志农产品,但其水分利用策略尚不清楚。本文基于氢氧稳定同位素示踪技术研究该地区降雨同位素特征及影响因素,利用多元线性混合模型方法量化不同来源水分对芒果树根系吸水的贡献比例,揭示芒果树生育期内水分利用策略。结果表明：（1）研究区氢氧稳定同位素具有明显的季节变化,δ值和氘盈余（d）具有旱季富集、雨季贫化的规律,建立了研究区的大气降水线方程：δD=8.2587δ18O+12.308,δD和δ18O值有极显著相关性（r=0.9968, n=35, P<0.001）;(2)季风气候影响下大气降水稳定同位素值具有显著的降雨量效应和反温度效应（P<0.05）;(3)在芒果花期、幼果期、果实膨大期和成熟期,土壤水氢氧稳定同位素总体上随土壤深度的增加而变贫;在花期和幼果期,芒果树对各层次土壤水分及地下水利用比例较为均匀,果树膨大期和成熟期则主要利用深层次土壤水及地下水,表明该地区芒果树主要以深层次土壤水及地下水为水源,说明芒果树更接近于保守型水分利用策略。降雨氢氧稳定同位素特征反映了该地区干热的气候特征,芒...     

植物衰老的分子机制及其调控

综述了植物衰老的意义和影响衰老的内部、外部因素 ,并从分子水平上探讨了植物衰老的机制及其遗传学调控     

植物黄酮在缓解奶牛热应激上的应用前景

奶牛是一种耐寒畏热的动物,当奶牛对环境温度的适应能力超过其阈值时就会产生热应激。热应激对奶牛的生产性能、抗氧化能力、免疫机制、内分泌和代谢产生不利影响,是阻碍奶牛业健康发展的一大问题。近年来,植物提取物作为一种兼具营养价值和保健价值的饲料添加剂被广泛应用。植物黄酮作为一种存在广泛的植物提取物,具有提高家畜生产性能和抗氧化能力、增强机体免疫力和抗炎能力、调节机体代谢等功效。因此,植物黄酮可以对症治疗奶牛热应激。本文将从热应激对奶牛生产性能、抗氧化能力、免疫机制、内分泌和代谢的影响以及近些年来将植物黄酮用于改善动物热应激的相关研究进行综述,以期为植物黄酮用于缓解奶牛热应激的深入研究提供理论支持。