酸性土壤中决明属牧草高效根瘤菌的分离及筛选

为提高豆科决明属（Chamaecrista spp.）牧草的结瘤能力和固氮效率，促进决明属牧草在酸性土壤中的应用及推广，本研究以圆叶决明（Chamaecrista rotundifolia）和羽叶决明（Chamaecrasta nictitans）为试验材料，通过分离、纯化、nodA基因鉴定等方法，从酸性土壤里决明属牧草的根瘤中分离到10株候选根瘤菌株系。16S rDNA测序及系统发育树分析表明，这10株根瘤菌均属于慢生型根瘤菌。回接试验表明，上述10株根瘤菌均能与圆叶决明共生，形成根瘤。与不接种的对照相比，其固氮酶活性为0.08~4.65 μmol·g^-1·h^-1，植株干重、SPAD值和氮含量分别提高了99.17%~372.14%，399.27%~789.05%，235.00%~1043.33%。其中，4株根瘤菌TXR2，TXN1，WYSR1，JYN6对圆叶决明氮营养贡献最大，并且TXN1与宿主共生形成的根瘤数目最多，而JYN6的固氮酶活性最高。说明本研究分离鉴定到4株决明高效根瘤菌，具有较好的应用前景。     

环剥与不同环割方法对糯米糍荔枝增产效应的研究

对糯米糍荔枝进行螺旋环剥与不同方法环割研究螺旋环剥与不同的环割方法对糍米糯荔枝冬梢的控制促花、保果增产效应的影响。研究结果表明螺旋环剥和不同环割方法在控稍促花方面能有效的控制糯米糍荔枝冬梢的萌发与促进花和花穗的生成;在保果增产方面,螺旋环剥、环割2处与同株50%主干枝条环割2处都能增加糯米糍荔枝的果穗枝条数与株产量,但环割1处反而降低了糯米糍荔枝的果穗枝条数与株产量。     

Evaluation of Cassia fistula meal as a replacement for soybean meal in practical diets of Oreochromis niloticus fingerlings

This study was undertaken to determine the replacement value of Cassia fistula seed meal (CFM) for soybean meal (SBM) in practical diets of Oreochromis niloticus fingerlings. Five practical diets (350 g kg^?1 crude protein) containing 0 g kg^?1 (control), 170 g kg^?1 (diet II), 340 g kg^?1 (diet III), 509 g kg^?1 (diet IV) and 670 g kg^?1 (diet V) substitution levels of CFM for SBM were formulated and fed to triplicate groups of O. niloticus fingerlings (mean initial weight of 10.22 ± 0.03 g) for 70 days. Fish mortality increased linearly with increase in inclusion levels of CFM in the diet. Growth and diet utilization efficiency were depressed in fish fed diets containing CFM at varying inclusion levels. Feed conversion ratio, specific growth rate and protein efficiency ratio of O. niloticus fed on diet containing 170 g kg^?1 substitution level of CFM were similar (P > 0.05) to the control diet. Digestibility of the different diets decreased with increase in inclusion levels of CFM. Fish fed diet containing 670 g kg^?1 CFM had significantly lower carcass protein. However, no significant differences were observed in carcass protein and lipid contents between fish fed the control diets and diet containing 170 g kg^?1 CFM. The most efficient diet in terms of cost per unit weight gain of fish was obtained in 170 g kg^?1 CFM dietary substitution.     

Root distribution ofDactyladenia (Acioa) barteri andSenna (Cassia) siamea in alley cropping on Ultisol. I. Implication for field experimentation

Root observations were carried out on a typic Paleudult in the humid forest zone of south eastern Nigeria in an alley cropping trial usingDactyladenia (Acioa) barteri andSenna (Cassia) siamea as hedgerow trees and the interrow space planted to maize/cassava intercrop. Rooting depth ofD. barteri andS. siamea exceeded 1.6 m. Lateral root propagation ofS. siamea was 15 m, and ofD. barteri was 5 m from the hedgerows. The whole no-tree control plot was within the range of roots of the adjacent hedgerows. Rooting density and depth ofS. siamea in the no-tree control plot was generally higher than of cassava.S. siamea and cassava root density were inversely correlated. Assuming radial symmetry of root propagation, water and nutrients were available from an area 6.1 and 2.3 times larger than the allocated plot size ofS. siamea andD. barteri, respectively. Data obtained in alley cropping trials, not considering lateral root propagation, can be invalidated through exploitation of the no-tree control treatment and nutrient acquisition by hedgerow species from a larger area than allocated, thus underestimating and overestimating the performances of the respective treatments. Possible alternative measures for avoiding root interference are discussed but no good solution can be given.     

楸树嫩枝扦插繁育试验

[目的]为促进楸树的开发与推广提供依据。[方法]利用激素种类、扦插基质、激素浓度、处理时间4个因素进行楸树嫩枝扦插育苗试验,探讨影响楸树生根的主要因子。[结果]以珍珠岩作扦插基质生根最好,生根率达17.77%;ABT1号生根粉500 mg/kg处理生根效果较佳,生根率达11.93%;处理时间以120 min为好,生根率达14.17%。扦插基质对生根的影响最大,其次是处理时间与激素浓度。3种激素各浓度处理平均生根率由高到低依次是:IBA>ABT1号生根粉>NAA,随着浓度的增加,生根率降低。ABT1号生根粉、500 mg/kgIBA处理楸树插穗2 h,生根率分别比对照增加82.6%、87.4%。[结论]用珍珠岩作扦插基质,500 mg/kg ABT1号生根粉处理2 h,楸树嫩枝扦插生根效果最好,生根率达30.8%。     

黄槐大花品种选育中的花器官因子相关性分析

为选育大花黄槐品种,在大田条件下调查黄槐花器官5项因子(花瓣长、花瓣宽、花丝长、果柄长和雌蕊长),运用Excel统计软件作因子间相关与回归分析和t检验,对黄槐花器官因子间进行相关性研究。结果表明:黄槐花器官5项主因子里花瓣长与花瓣宽呈极显著正相关,花瓣宽与花丝长呈极显著正相关。这种正相关关系,可以为大田条件下选育大花黄槐品种提供理论依据。     

福建决明属植物种子的蒽醌类物质比较

应用紫外可见分光光度法和高效液相色谱法测定福建8种决明属植物种子生品蒽醌类物质的含量,并对决明子药材评价指标进行初步分析.结果表明:不同决明属植物种蒽醌类物质总含量及组成有明显不同,钝叶决明的橙黄决明素、大黄酸含量最高,分别为1.383,0.557 mg·g-1;决明的大黄酚含量最高,为0.902mg· g-1;双荚决明和望江南的大黄素甲醚含量较高,分别为1.850、1.310 mg·g-1.翅荚决明、羽叶决明、圆叶决明均未检出橙黄决明素,大黄酸、大黄素,大黄酚、大黄素甲醚.随着植物种的变化,决明属植物种子的大黄素甲醚变异系数最高为0.302,橙黄决明素变异系数次高为0.278.大黄酸与大黄酚、橙黄决明素的相关系数分别为o.809,o.749.     

昆明引种的双荚决明花挥发油化学成分分析

用水蒸汽蒸馏的方法提取了双荚决明花的挥发油,通过GC-MS对其进行分析,用面积归一化法测定各化学成分的相对百分含量。实验结果表明,双荚决明花挥发油的化学成分可分为脂肪酸、酚类及烷烃类,其中十六烷酸（脂肪酸类化合物）的含量最高,为47.850%;烷烃类化合物9个,总含量为37.876%,以正二十七烷的含量较高,为12.594%;甲基-二特丁基-苯酚含量为5.874%。本实验结果为双荚决明的进一步研究提供了参考。     

Hepatoencephalopathy syndrome due to Cassia occidentalis (Leguminosae,Caesalpinioideae) seed ingestion in horses

Cassia occidentalis is a bush from the Leguminosae family, subfamily Caesalpinoideae, and is a toxic plant of veterinary interest due to the occasional contamination of animal rations. This report describes the clinical and histopathological findings of an outbreak of C. occidentalis poisoning in horses. Twenty mares were poisoned after consuming ground corn contaminated with 8% of C. occidentalis seeds. Of the 20 animals affected, 12 died: 8 mares were found dead, 2 died 6 h after the onset of clinical signs compatible with hepatic encephalopathy and the 2 other animals were subjected to euthanasia 12 h after the onset of the clinical signs. The remaining 8 mares presented with mild depression and decreased appetite, but improved with treatment and no clinical sequelae were observed. In 6 animals that underwent a necropsy, an enhanced hepatic lobular pattern was noted and within the large intestine, a large number of seeds were consistently observed. Hepatocellular pericentrolobular necrosis and cerebral oedema were the main histological findings. In one mare, there was mild multifocal semimembranosus rhabdomyocytic necrosis and haemorrhage. Seeds collected from intestinal contents and sifted from the culpable feedstuff were planted. Examination of the leaves, flowers, fruits and seeds of the resultant plants identified C. occidentalis. Horses poisoned by C. occidentalis seeds demonstrate clinical signs associated with hepatoencephalopathy and frequently die suddenly. Lesions primarily involve the liver and secondarily, the central nervous system. Cassia occidentalis poisoning should be considered a differential diagnosis in horses with hepatoencephalopathy and special caution should be taken with horse rations to avoid contamination with seeds of this toxic plant.     

内蒙古大兴安岭俄罗斯大果沙棘嫩枝扦插技术研究

针对俄罗斯大果沙棘(浑金)在内蒙古大兴安岭库都尔林业局通过不同基质的配比,不同生根剂的使用,同时优选最适宜的温湿环境、光照强度等因子,采用容器培育嫩枝扦插苗的方式培育俄罗斯大果沙棘(浑金)扦插苗,从而总结出内蒙古大兴安岭高寒地区俄罗斯大果沙棘(浑金)的嫩枝扦插技术体系,提高其苗木质量和产量,为该品种在林区大面积推广种植提供关键技术和优质苗木。