Detection of full and limited amphidromous migratory dynamics of fish in Caribbean rivers

All native fishes living in the Caribbean island rivers are considered diadromous but few species have been validated as diadromous. In Guadeloupe (Lesser Antilles) as well as in the other tropical islands, the riverine habitats are subject to strong anthropogenic pressure due to resource modifications or dams. The management of fish biodiversity requires knowledge concerning their life history traits and behaviour that are still unknown for most species at a local scale and at the whole distribution area of the species. In a Guadeloupe river, we inferred the migratory patterns of four freshwater fishes common to Caribbean rivers by the analysis of otolith microchemistry. We found two species Eleotris perniger (Eleotridae) and Sicydium plumieri (Gobiidae) to be completely amphidromous with a marine larval phase and a freshwater adult phase. Agonostomus monticola (Mugilidae) was also found to be amphidromous in this system. The fourth species Gobiesox cephalus (Gobiesocidae) showed elemental ratios suggesting an estuarine larval phase and was defined as “limited amphidromous”. The identification of such life history traits, with limited dispersion abilities, argues for specific management measures in tropical island rivers at a basin scale for the conservation of biodiversity.     

Diet composition, herbage intake and digestibility in Inner Mongolian Cashmere goats grazing on native Leymus chinensis plant communities

The botanical composition, intake and digestibility of the diet selected by Inner Mongolian Cashmere goats grazing on a native Leymus chinensis plant community were measured in two grazing periods (June and August) using the n-alkane markers. In each grazing period, 48 Inner Mongolian Cashmere goats (24 wethers and 24 does with an average live weight of 22.1 ± 1.2 kg and 19.6 ± 0.8 kg, respectively) were divided in two groups (G1: grazing group; G2: cage-fed group) of 24 animals each. Based on the observation of G1 grazing behaviour, G2 goats were fed on herbage obtained by a simulative method and were housed in metabolism cages to determine the alkane faecal recoveries. Diet composition was estimated by comparing the odd-chain n-alkane pattern (C₂₅–C₃₅) of the selected plant species with the n-alkane faecal concentrations, corrected for their incomplete faecal recovery. The alkane pair C₃₂:C₃₃ and C₃₆ alkane were used to estimate intake and diet digestibility, respectively. The results showed that the increase of herbage availability from June to August, resulted in higher (P < 0.05) DM, CP, ME, ADF and NDF intake of both wethers and does, with no evident changes in ADF and NDF intake in does., The intake of nutrients differed significantly between wethers and does in both experimental periods, except for NDF in EP1 and ME in EP2. Differences between grazing seasons and goats' sex in nutrients digestibility were not observed. Diet composition indicated seasonal differences, being Sonchus brachyotus, Artemisia frigida and Phragmites communis the main components of the diet in June. However, Suaeda corniculata, Chloris virgata, Xanthium sibiricum and Echinochloa crusgalli became the main diet components in August. Moreover, the sex affected significantly the diet choices in both grazing periods.     

细胞水平高赖氨酸小麦选择的研究

在野生植物蓬蘽果汁饮料研制中不添加任何色素、香精及防腐剂, 所得产品色、香、味独特逼真, 是一种集天然、营养和保健于一身的新型理想饮品。研制结果表明: 蓬蘽果汁饮料以采用鲜果不破碎取汁法, 1: 2的稀释度,以及8% 糖度、0. 20%酸度或10%糖度、0. 25%酸度的配比为佳。     

黄瓜品种与其根围主要病原菌的拮抗菌之间关系的研究

对具有不同抗性和品质的黄瓜品种与其根围、根表的主要病原菌（Ｒｈｉｚｏｃｔｏｎｉａｓｏｌａｎｉ和Ｐｙｔｈｉｕｍａｐｈａｎｉｄｅｒｍａｔｕｍ）的拮抗菌之间关系的研究结果表明：黄瓜在不同生长时期,两者的关系不一致。在出苗后２ｄ,７ｄ时,抗病品种根围拮抗菌的数量多于感病品种;在出苗后１４ｄ,在这６个品种中,Ｒ．Ｓｏｌａｎｉ与Ｐ．ａｐｈａｎｉｄｅｒｍａｔｕｍ根围、根表的拮抗菌数均达到最高峰,且品质优良但相对较感病的两个品种浙农１８、上海洋行根围、根表拮抗菌数明显高于其他品种;经Ｄｕｎａｎ＇ｓ多重比较表明,Ｒ．ｓｏｌａｎｉ的根围、根表拮抗菌数与Ｐ．ａｐｈａｎｉｄｅｒｍａｔｕｍ相比,两者差异均达极显著水平,前者明显高于后者。     

兰考泡桐不定芽自然接干规律研究

在相同立地条件下,分别对兰考泡桐林分、四旁树和孤立木样木（包括依靠不定芽自然接干的１５０株和人工接干的３０株）与接干有关的生长因子进行实测,并建立兰考泡桐接干形率与主要生长因子的数学模型;不同栽植方式对接干形率、第一接干高均有显著影响;第一接干高与苗高呈负相关,但相关性不显著;第一接干发生时的树龄以３～４ａ对接干形率的影响最佳,５ａ以后接干效果较差．同时对兰考泡桐不定芽接干各种树形图谱及其在各栽植条件下所占的比例、兰考泡桐第一接干发生时的树龄分布及林分、四旁树、孤立木条件下的相应接干方式等问题进行了探讨．     

中华蜜蜂精液的冷冻贮存技术(英文)

中华蜜蜂精液在液氮（－ １９６ ℃） 中贮存１２１ ｄ,精液与含有８％ 二甲亚砜的三羟基氨基甲烷缓冲稀释液以１∶１．５ 混合,不用平衡,在广口保温瓶中距液氮面２ ｃｍ 或５ ｃｍ 处预冻,在３５～３９ ℃水浴中解冻,可产生较好的解冻后活力比率（超过６０％ ）．当室温高于２０ ℃时（４ 月份）,样本必须于１３ ℃下平衡０．５ ｈ 左右,其解冻后活力比率可达３０％ ．春季采集并冷冻的样本,其解冻后活力不如冬季采集并冷冻的．用在液氮中贮存了１～１２１ ｄ 的精液分别以 ４～５ μ Ｌ的剂量给 ２４ 只处女王人工授精,４ 只开产但首先产的不是受精卵．解冻后的精液能够于１３ ℃下保存４６ ｈ．磺胺不能用于精子冷冻．