Lolium multiflorum density responses under ozone and herbicide stress

Adaptations to overcrowding of individual plants result in density dependant control of growth and development. There is little information on how anthropogenic stresses modify these responses. We investigated whether combinations of diclofop‐methyl herbicide and tropospheric ozone alter the pattern of expected growth compensation with density changes resulting from intraspecific competition in Lolium multiforum Lam (Poacea) plants. Individual plant vegetative parameters and total seed production were assessed for plants growing under various densities and different herbicide rates and ozone treatments. The stressors differently changed the frequency distribution for average individual plant weight resulting from increasing densities. Only herbicide affected seedling mortality. Plants were able to compensate during grain filling maintaining similar seed production – density relationships in all treatments. Our findings contribute to the understanding of the impact of stress factors on the demographic changes in plant populations. Important ecological implications arise: (i) contrasting responses to ozone and herbicide, alone and in combination of individual plants resulted in different biomass – density relationships; (ii) stress effects on plant populations could not be predicted from individual responses; and (iii) changes in competitive outcome by single or combined stress factors may alter the expected genotype frequency in a crowded population with few dominant individuals.     

高温高湿条件下意大利黑麦草青贮技术研究

研究以水田冬闲期栽培的意大利黑麦草(Lolium multiflorum)为材料,结合常规的青贮方法进行了小规模控制实验,试验设计了隔水(将青贮过程中产生的渗出液排出)和不隔水,以及不同添加物的青贮处理.青贮结束后,对青贮黑麦草的品质和营养价值进行评定,探讨不同处理对黑麦草青贮的作用效果,以及南方高温高湿条件下青贮黑麦草的合理方法和最佳条件.结果发现,对黑麦草进行隔水添加乳酸的青贮处理从感观评定、pH值和营养成分的分析结果来看,都在一定程度上优于其他处理,由此可以认为隔水添加乳酸的处理相对实现了较稳定和较优质的青贮.     

Changes in NO3− and K+ uptake by four species in flowing solution culture in response to increased irradiance

Net rates of NO₃^? and K⁺ uptake were compared for oilseed rape (Brassica napus L. cv. Jet neuf), perennial ryegrass (Lolium perenne L. cv. S23), Italian ryegrass (Lolium multiflorum Lam. cv. Augusta) and wheat (Triticum aestivum L. cv. Fen-man) in flowing solution culture during a 4-day sequence of low-low-high-high natural irradiance. Concentrations of NO₃^? (10 μM) and K⁺ (2.5 μM) in solutions were maintained automatically and hourly variation in net uptake of these ions was measured. During the 2 days of low irradiance (<1 MJ m^?2 day^?1) the uptake rates of both ions by all species were low at <1 mmol NO₃^?, m^?2 h^?1 and <0.4 mmol K⁺ m^?2 h^?1. Uptake increased in each species during the first day of high irradiance (7.90 MJ m^?2 day^?1) to >4 mmol NO₃^? m^?2 h^?1 and >1.4 mmol K⁺ m^?1 h^?1. These higher rates were maintained throughout the following night. The lag-time between maximum irradiance and the onset of the highest acceleration in uptake was greater for NO₃^? (5–8 h) than for K⁺ (≤1 h) in rape, wheat and Italian ryegrass. Uptake of NO₃^?, by perennial ryegrass showed an almost constant acceleration for 18 h following maximum irradiance. In all species the measured maximum inflows (uptake rate per unit root length) of both ions were greater than theoretical maximum potential inflows to a non-competing infinite-sink root in soil, by factors of 7 and 36, respectively, for NO₃^? and K⁺, averaged over all species.     

神农架菊属一新变种

本变种与原变种的主要区别在于花、叶具浓香气,叶片较小,深绿色,上面叶脉明显隆起,下面具极小腺体;头状花序较小,通常直径不超过1.5厘米。生于2000米以上高山旷地或灌丛边。与少数原变种混生成群落,有一定数量。     

Construction of a primary RH panel of Italian ryegrass genome via UV-induced protoplast fusion

Symmetric and asymmetric somatic hybrids were produced via protoplast fusion between common wheat ( TRITICUM AESTIVUM L.) cv. "Jinan 177" and Italian ryegrass ( LOLIUM MULTIFLORUM Lam.). The ryegrass without or with UV irradiation was used as a donor, providing a small amount of chromatin. In these somatic hybrids, most ryegrass chromosomes have been confirmed preferential elimination and the somatic hybrid calli and plants showed wheat-like morphology. Some of the hybrid lines were used for the analysis of distribution and heredity of donor DNA in the hybrid genome and the possibility of establishing a radiation hybrid (RH) panel of the ryegrass in the present experiment. These hybrids, subcultured for two and three years, retained the ryegrass DNA examined by RFLP and GISH analysis, respectively. Distribution of the ryegrass DNA in the wheat genomes of 20 single-cell individuals, randomly selected from hybrid cell lines produced, were analyzed by 21 ryegrass genome specific SSR markers. The average frequencies of molecular marker retention in symmetric hybrid lines (UV 0), as well as asymmetric hybrid lines from UV 30 s and 1 min were 10.88, 15.48 and 33.86, respectively. It was suggested that the UV dose increased the introgression of donor DNA into wheat genome. The ryegrass SSR fragments in most asymmetric hybrid cell lines remained stable over a period of 2 approximately 3 years. This revealed that those asymmetric somatic hybrids are suitable for the introgression of ryegrass DNA into wheat, and for RH panel and RH mapping.     

吉林槭属一新变种

槭属一新变种,即长白花楷槭Acer ukurunduense Trautv.et Mey.var.changbaishanense W.Cao.     

球兰属一新变种

<正> 彩叶球兰是笔者在福州地区进行攀援植物种质资源调查过程中发现的一个球兰属新变种,作为观赏植物引种栽培两年以来,生长良好,性状稳定,植株枝柔叶翠、彩叶斑斓、花序大型且耐荫性强,有较高的观赏价值。     

湖南Ji木属一新变种

发表了Ji木属一新变种,即彩花Ji木Loropetalum chinense(R.Br.)Oliver var.coloratum C.Q.Huang.     

新疆葱属—新变种

发表新疆葱属———一新变种 :哈马河葱     

百山祖八角——八角属一新变种

<正> 百山祖八角 新变种 Illicium jiadifengpi B. N. Chang var. baishanenze B. N, Chang et S. H.Ou, var. nov. A typo recedit segmentis perianthii 5—10 crassioribus, carnosulis, triangulis, ovato-triangttlis ad ellipticis, 4—11 mm longis, 4—7 mm latis. Zhejiang: Qingyuan Xian, baishanzu, alt, 1100 m, M. H. Wu 7601, baishanzu, alt, 1500m, M. H. Wu 7724(Typus in Herb. Inst. Bot. Guangxi conservatur)     

广西黄皮属一新变种

<正> 弄岗黄皮 新变种 CLausena yunnanensis Huang var.longgangensis C.F.Liang et Y. X. Lu, var. nov. A typo differt ramulis,rhachibus,petiolulis,pedunculis et pedicellis fructificantibus dense pubescentibus,foliolis subtus apprime ad costas dense barbatis.     

山东苹果属一新变种

本文发表了苹果属一新变种, 即歪把海棠Malus prunifolia (Willd.)Borkh.var.obliquipedicellata X.W.Li et J.W.Sun     

山东绣线菊属一新变种

本文发表了绣线菊属一新变种, 即直果绣线菊Spiraea chinensis Maxim.var.erecticarpa Y.Q.Zhu et X.W.Li     

中国八角属一新变种

广东产八角五新变种,宽叶八角Illicium dunnianum Tutcher var.latifolium Q.Lin。     

甘肃萱草属─新变种

甘肃萱草属─新变种孔红王庆瑞（甘肃天水师范高等专科学校生物系,天水７４１０００）（西北师范大学植物研究所,兰州７３００７０）关键词萱草属;对苞萱草;甘肃ＡＮＥＷＶＡＲＩＥＴＹＯＦＨＥＭＥＲＯＣＡＬＬＩＳＦＲＯＭＧＡＮＳＵ￥ＫｏｎｇＨｏｎｇ（Ｄｅｐａｒ...