Variation in Growth and Yield Performance of Seventeen Water Chestnut Accessions (Trapa spp.) Collected from Asia and Europe

Abstract

Water chestnut is an aquatic annual herb, and its fresh, edible fruit is a valuable crop. The huge variation in growth and yield of water chestnuts has not been well documented. In this study, the yield performance of 17 water chestnut lines, eight from China (Trapa acornis L., T. bicornis L., T. bispinosa Roxb, T. quadrispinosa Roxb), one from France (T. natans L.), one from India (T. bispinosa Roxb.), three from Italy (T. natans L.), three from Japanese (T. incisa L., T. japonica Flerov, T. natans.L. var. rubeola Makino), and one from Korean (T. japonica Flerov.) were cultivated in Saga City, Japan during the summer, 2005, and the morphological characters of their fruit were analyzed. European lines were early flowering, but had a lower yield due to poor canopy density and lower rosette density. All the Asian lines had a higher rosette density. In spite of the smaller number of fruits per rosette, the Chinese lines had a higher yield than the other lines because the fruit was larger. The yield performance of the Indian line was similar to that of the Chinese lines. The Korean and Japanese lines produced a large number of small fruits per unit land area. Apart from the variation in fruit size, a huge variation in shape including the height, width and the spines were observed. Path analysis revealed that productive rosette number m-² and the single fresh fruit weight are two direct yield determinants while number of fruits per rosette has indirect negative influence on yield via productive rosette number and single fruit weight.     

Comparison of Growth and Yield Performance of Several Water Chestnut Species Collected from Southwestern Japan and Middle China

Summary

Vegetative growth characters and yield components of water chestnuts distributed in Japan and China were investigated for 12 local lines of 6 species ; i.e., 5 small and 2 medium fruit lines from Japan, and 5 large fruit lines from China. The materials were transplanted and grown in a flooded field usually used for rice cultivation in Saga City in 1995. The lines from China had higher rates of foliage formation, developed emersed leaves earlier and maintained them longer compared with the Japanese lines. The small fruit lines of Japan had the shortest growing period, although the number of rosettes was larger. The fruit yield of the small, medium and large fruit lines, was 250 to 400 g m^?2, about 600 g m^?2 and 600 to 1,000 g m^?2, respectively. The fresh weight of well-ripened fruit was 1 to 5 g for the small fruit lines, 5 to 10 g for the medium fruit lines and more than 10 g for the large fruit lines. The number of fruits per m2 increased as the fruit size of the lines decreased. However, the productivity of the water chestnut was higher in the large fruit lines than in the small or medium fruit lines.     

菱角萤叶甲取食量研究

[目的]为国外菱角生物防治的天敌筛选提供理论依据。[方法]研究温度对不同地理种群菱角萤叶甲幼虫和成虫取食量的影响。[结果]在一定温度范围内取食量随温度升高而逐渐增大（16~28℃）,当温度过高（〉31℃）时取食量开始减少 幼虫、成虫取食量最大值一般出现在温度28℃左右 与幼虫相比,成虫取食量较大,危害期较长 建立了取食量与温度间关系的模型,经检验能较好地拟合试验数据 同时对不同地理种群菱角萤叶甲的取食量进行了比较,结果表明不同地理种群间取食量有了很大差别,保山种群的世代取食量是泰安种群的2倍。[结论]温度是影响菱角萤叶甲生长发育的重要环境因子,保山种群是国外控制菱角的潜在理想天敌。     

Amelioration of calcareous saline sodic soils through phytoremediation and chemical strategies

Abstract. The worldwide occurrence of saline sodic and sodic soils on more than half a billion hectares warrants attention for their efficient, inexpensive and environmentally acceptable management. These soils can be ameliorated by providing a source of calcium (Ca²⁺) to replace excess sodium (Na⁺) from the cation exchange sites. Although chemical amendments have long been used to ameliorate such soils, the chemical process has become costly during the last two decades in several developing countries. As a low‐cost and environmentally acceptable strategy, the cultivation of certain salt tolerant forage species on calcareous sodic and saline sodic soils, i.e. phytoremediation, has gained interest among scientists and farmers in recent years. In a field study conducted at three calcareous saline sodic sites (pH_s=8.1–8.8, EC_e=7.8–12.5 dS m^–1, SAR=30.6–76.1) in the Indus Plains of Pakistan, we compared chemical and phytoremediation methods. There were four treatments; two involved plants: Kallar grass (Leptochloa fusca (L.) Kunth), and sesbania (Sesbania bispinosa (Jacq.) W. Wight). The other two treatments were uncropped: soil application of gypsum and an untreated control. All treatments were irrigated with canal water (EC=0.22–0.28 dS m^–1). The plant species were grown for one season (5–6 months). Sesbania produced more forage yield (34 t ha^–1) than Kallar grass (23 t ha^–1). Phytoremediation and chemical treatments resulted in similar decreases in soil salinity and sodicity, indicating that phytoremediation may replace or supplement the more costly chemical approach. The soil amelioration potential of sesbania was similar to that of the Kallar grass, which suggests that moderately saline sodic calcareous soils can be improved by growing a forage legume with market value.     

二棘血蜱叮咬中华硬蜱纯化抗原免疫接种宿主后的交叉免疫反应

选用中华硬蜱105kD柱层析纯化抗原对新西兰兔进行免疫接种,再用二棘血蜱进行叮咬,并与单纯二棘血蜱叮咬组和佐剂对照组进行对比,以探讨不同种属硬蜱之间的交叉免疫抗性。结果显示:单纯二棘血蜱叮咬组吸血量为181 3±44 3mg,而二棘血蜱叮咬由中华硬蜱105kD纯化抗原免疫接种组和佐剂对照组新西兰兔后其吸血量分别为102 1±25 3mg和168 5±40 9mg,纯化抗原免疫接种组较单纯二棘血蜱叮咬组和佐剂对照组吸血量分别下降43 7%和39 4%(P<0 01)。同时,纯化抗原免疫接种组也较单纯二棘血蜱叮咬组和佐剂对照组产卵量有显著下降。该研究结果表明中华硬蜱和二棘血蜱之间存在着交叉免疫反应。     

南湖菱套养泥鳅种养结合模式试验及技术要点

比较了南湖菱套养泥鳅与单作南湖菱的产量及效益情况,并提出了科学的南湖菱套养泥鳅技术要点。结果表明,南湖菱套养泥鳅与单作南湖菱相比,菱产量降低200．25kg／667m2,增加泥鳅产量209．25kg／667m2,产值增加8005．50元／667m2,成本增加6305元／667m2,效益增加1695．50元／667m2,另外,套养泥鳅还可减少杀虫剂的使用次数及使用量,因此南湖菱套养泥鳅是一种经济、高效、安全、生态的种养结合模式。     

稀土元素铈缓解镉对菱叶的毒害效应研究

利用不同浓度的Cd^2＋和不同浓度的Cd^2＋加5mgL^-1Ce^3＋分别处理菱植株，对菱叶中的叶绿素、脯氨酸、保护酶——超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性的动态变化进行了研究：实验结果表明：在镉胁迫下，随着镉浓度的上升（0～4mgL^-1）菱叶中叶绿素含量下降，SOD、POD活性和脯氨酸含量在镉低浓度时上升而高浓度时下降，相反，CAT活性在镉低浓度时下降而高浓度时上升。与镉离子单一处理相比，Cd^2＋-Ce^3＋复合处理中的Ce^3＋可提高叶片中叶绿素的含量和SOD、POD的活性，尤其是在1mgL^-1 Cd^2＋加5mgL^-1Ce^3＋复合处理中，POD活性较对照提高了8．33倍。由此表明，5mgL^-1Ce^3＋对低浓度镉引起菱叶片的毒害作用有较为明显的缓解效果。     

国产菱属植物数量分类学研究

应用数量分类的方法,将采自国内12个省的37个居群用31个性状进行Q、R聚类分析和主成分分析(PCA),探讨了国产菱属植物间的亲缘关系,同时对分类性状进行了评价.结果表明:国产菱属的37个居群可以划分成细果野菱和野菱两个种,栽培类型由于受人为影响较大,不能作为种一级来处理.31个性状中以果体大小的性状最为重要,可作为种的划分依据,而腰角的有无、果冠大小等性状则作为种下分类群的划分依据.     

正交试验法优化菱角多糖提取工艺

菱角多糖具多种药理活性。为了优选出热水浸提法提取菱角多糖的最佳工艺条件,本研究以菱角多糖的提取率为指标,选取料液比、提取温度、提取时间为影响因素,在综合单因素实验的基础上,采用L₉(3⁴)正交试验进行工艺优化,采用苯酚—硫酸法测定多糖的含量。结果表明：多糖提取率随料液比的增加,呈先升后降的趋势,料液比为1:30时提取率最高,为2.72%;提取温度为70℃时,多糖提取率最高,为2.96%;提取时间为120 min时,提取率最高,为1.81%,之后提取率减少。综合以上单因素试验结果进行正交试验,得到菱角多糖的最佳提取工艺为料液比1:30、温度60℃、时间120 min。热水浸提菱角多糖工艺操作简便易行,具有实用价值,可依据该工艺条件制定菱角多糖提取工艺。     

间种式植物人工湿地对校园生活污水净化的效果研究

[目的]研究人工湿地景观设计效果及不同人工湿地植物对生活污水的处理效果.[方法]选择美人蕉＋菖蒲＋野菱＋轮叶黑藻构成人工湿地植物组合,测定该组合对试验水样NH3-N、CODCr、TP的去除率.[结果]组合植物对NH3-N的削弱作用最为显著,其次是CODCr、TP.水力停留时间3d对NH3-N、CODCr、TP的去除率分别为：50.25％～ 99.40％、37.10％～72.83％、-28.48％ ～91.81％;最高去除率分别为99.40％、72.83％、91.81％.第一周期到第四周期NH3-N、CODCr、TP的去除效率曲线表明：曲线的斜率呈现出增加趋势.[结论]该研究可为复合人工湿地植物群落对生活污水的去除效果提供重要的运行参数和技术支持.