湖南烟区土壤pH分布特点及其与土壤养分的关系

测试分析了湖南烟区1089个土壤样本的pH,并分析了其与土壤养分的关系。结果表明：湖南烟区土壤pH总体适宜,平均为6．52,变异系数为16．81％;pH处于最适宜烤烟生长的5．5～6．5间的土壤样本占总样本数的26．91％;pH处于适宜烤烟生长的5．0～7．0间的土壤样本占52．71％。湖南不同烟区土壤pH大小表现为：湘南〉湘北〉湘西〉湘东;烟区不同土壤类型pH大小表现为：鸭屎泥〉黄壤土〉青泥田〉黄灰土〉黄泥田〉红黄泥。土壤pH与土壤有机质、全氮、速效磷、速效钾、有效锌、有效铁、水溶性氯、交换性钙和交换性镁的相关性均达1％极显著水平。土壤pH分组后,土壤养分含量在组间存在极显著差异。湖南烟区pH在5．5～6．5间的土壤的有机质、全氮、速效磷、有效锌和水溶性氯含量能够满足优质烤烟生长需求,有效锰、有效铁、交换性钙和交换性镁含量能满足烤烟的正常生长需求,有效钾和有效铜含量偏低,但尚未引起烤烟的缺素症状。     

和田绿洲水文气象要素分形特征与R/S分析

基于和田绿洲半个世纪（1954-2003年）以来实测水文气象资料,应用Kandell秩次相关检验法进行趋势性分析,结果表明：气温、蒸发的增加趋势显著,降水、相对湿度与河川径流量存在不显著的减少趋势。R/S分析结果表明,绿州内各水文气象要素的变化具有持续性,但不同季节的持续强度不同,降水和相对湿度的持续强度夏季大于冬季,其余表现为冬季大于夏季。分形结果显示,各水文气象要素变化的趋势性和复杂程度不同,其中玉龙喀什河径流量〉喀拉喀什河径流量〉相对湿度〉降水量〉平均气温〉蒸发量,即绿洲径流变化的趋势线最不明显,也最复杂。研究结果对了解绿洲气候资源、指导农业生产及预防灾害有参考作用。     

外源硝态氮对菊芋耐海水胁迫的影响

A hydroponic experiment with six treatments, i.e., 0% seawater （control）, 10% seawater, 25% seawater, 0% seawater ＋ N （7.5 mmol L-1 NaNO3）, 10% seawater ＋ N （7.5 mmol L-1 NaO3）, and 25% seawater ＋ N （7.5 mmol L-1 NaNO3）, was carried out to study the effect of nitrogen addition on the growth and physiological and biochemical characteristics of Jerusalem artichoke （Helianthus tuberosus） seedlings under seawater stress. The 10% seawater stress treatment had the least effect on plant growth while at 25% seawater growth was significantly inhibited. The malondialdehyde content and electrolyte leakage in leaves under 10% seawater were similar to those of the control, but significantly higher under the 25% seawater stress. The activities of superoxide dismutase, peroxidase and catalase in the leaves increased concomitantly with increasing seawater concentration and time. Proline and soluble-sugars in the leaves and Na^＋, K^＋, and Cl- contents in shoots and roots increased significantly with the concentration of seawater increasing. Nitrogen addition resulted in increasing fresh and dry weights of shoots and roots compared with seawater treatment without N. Nitrogen supplementation also significantly enhanced the activities of antioxidant enzymes in leaves. Addition of N to seawater enhanced the contents of proline and soluble-sugars in the leaves and K^＋ and total-N in the aerial parts and roots of H. tuberosus, but it resulted in declined concentrations of Na^＋ and Cl- in the aerial parts and roots. Nitrogen addition ameliorated the toxicity of seawater by improving the antioxidative enzymes, accumulating of proiine and soluble-sugars, and altering the distribution of inorganic ions in H. tuberosus.     

Australian Uromyces viciae-fabae: Host and nonhost interaction among cultivated grain legumes

Uromyces viciae-fabae, rust of faba bean, parasitizes other legume crops such as lentils (Lens culinaris) and field peas (Pisum sativum) in some environments. In this study we examined the host range of two Australian isolates of U. viciae-fabae collected and purified from a faba bean crop and classified as U. viciae-fabae ex V. faba. Field pea (P. sativum), chickpea (Cicer arientinum), lupin (Lupinus spp.), lentil (L. culinaris), and mung bean (Vigna radiata) genotypes were tested with these isolates, as well as resistant and susceptible genotypes of the faba bean host. Race specificity for these two pathogen isolates was observed on Vicia faba, with two faba bean genotypes showing partial resistance. Both U. viciae-fabae isolates also colonized field pea seedlings and successfully produced uredinia under glasshouse conditions, despite this fungus not being known as a pathogen of Australian field pea crops. No sporulation of either isolate of U. viciae-fabae ex V. faba was observed on any of the remaining legume species tested. However, obvious differences in fungal growth were observed, ranging from small infection sites with very rare haustorium formation in mung bean to more extensive growth and the development of potential uredinial structures in chickpea. These observations are discussed in relation to the phylogenetic relationship of these host and nonhost species.     

四种园林植物对遮荫的生理响应及耐荫性评价

以茶梅‘小玫瑰’、冠盖藤、聚花过路黄和兰花三七4种园林植物1年生苗为试验材料,遮荫处理4个月,研究不同遮荫处理(全光照、遮荫65%、遮荫80%和遮荫95%)对植株生长及生理生化指标的影响,并用隶属函数分析法对4种植物的耐荫性进行了综合评价。结果表明:茶梅‘小玫瑰’、兰花三七在4种遮荫处理下,4个月后株高均有所增长,但冠幅表现为在遮荫65%和遮荫80%条件下,均有一定的增长,在全光照和遮荫95%条件下为先增长后减小的趋势,冠盖藤覆盖度也出现此现象,聚花过路黄在4种条件下均能生长良好。随着遮荫度增加,4种植物叶片的叶绿素a、b以及叶绿素a+b含量均为先增后减,均高于对照,叶绿素a/b值总体呈现降低趋势;可溶性蛋白质含量均有所降低;相对电导率表现为冠盖藤为先降后增,其余3种植物均为增加的趋势;MDA含量表现为兰花三七为先降后增,其余3种植物均为降低的趋势;POD活性和SOD活性表现为先增后降,除冠盖藤SOD活性表现为先降后增。隶属函数分析法综合评价4种植物的耐荫性,耐荫性顺序为兰花三七>聚花过路黄>冠盖藤>茶梅‘小玫瑰’。     

Movement behaviour of large female yellow European eel (Anguilla anguilla L.) in a freshwater polder area

Due to a recruitment decline of more than 90% in 30 years, the European eel (Anguilla anguilla L.) has been classified by IUCN as critically endangered. Although the species has been studied intensively to obtain knowledge to improve management, studies about the resident yellow stage are relatively scarce. In this study, 52 large female yellow eels were tagged with acoustic transmitters in a Belgian polder system and tracked by a network of 23 automatic listening stations. We studied both circadian and seasonal movement patterns and the effect of environmental variables on these patterns. Large female yellow eels were most active at night in late summer and early autumn. A generalised linear mixed model showed that their movement is only slightly influenced by environmental variables. Moreover, as yellow eels show high site fidelity (i.e., the majority was detected only in the habitat type of their catch‐release location), they do not encounter many human‐induced connectivity problems in polder systems, which makes these systems highly suitable as eel growth habitat. These results can contribute to an effective eel management regarding habitat protection and restoration.     

Growing Degree Day: Noninvasive Remotely Sensed Method to Monitor Diet Crude Protein in Free-Ranging Cattle

The daily nutritional balance of free-ranging cattle is the net result of intake from available forage biomass and nutritive value weighed against the nutritional requirements of the animal. Plant phenology influences nutritive value. Plant phenology is dictated by time of year and an accumulation of photosynthetically active days. Growing degree day (GDD) is a concept that quantifies this relationship and has been used to predict nutritive value in perennial range grasses. GDD could be substituted for chemical analysis to inform grazing animal nutritional monitoring efforts. We hypothesized that in C4 grass-dominated rangelands, a cumulative GDD calculation would correlate with diet crude protein (CP) predictions obtained by fecal near infrared spectroscopy (FNIRS) from free-ranging cattle. Therefore, the objectives of our research were to evaluate the effectiveness of GDD to predict FNIRS-derived determinations of grazing cattle diet CP in 1) two groups of three individual animals grazing a small native pasture and 2) large commercial-scale herds grazing expansive rangelands. For the first objective, cumulative GDD and FNIRS-predicted diet CP were strongly correlated (r² = 0.76; P < 0.01). Relationships between cumulative GDD and FNIRS-predicted diet CP for the second objective varied considerably among ranches, ranging from a low r² of 0.05 (P = 0.871) to a high r² of 0.78 (P < 0.049). Similar values for individual ranch/year combinations were stronger; ranging from a minimum r² of 0.44 (P = 0.556) to a maximum of 0.95 (P = 0.051). The aggregate relationship between GDD and FNIRS-predicted CP for all ranch/year combinations was highly significant (r² = 0.37; P < 0.001), but the standard error was 1.86% CP. The noninvasive remotely sensed grazing animal nutritional monitoring method described here was accurate enough to inform tactical rangeland diet quality assessments but was not accurate enough to inform operational-scale grazing management decisions.     

华北地区十字花科芸薹属蔬菜上立枯丝核菌的病原生物学研究

 由丝核菌引起的十字花科蔬菜叶腐和茎基腐病在中国华北地区普遍发生,其中以河北、内蒙以及北京较为严重。2011~2018年,从华北地区不同省份具有典型叶腐和茎基腐症状的芸苔属蔬菜上分离获得95个丝核菌(Rhizoctonia spp.)分离物,大多数分离自发病植株的叶部,少数分离自茎基部。通过细胞核染色,87株菌属于多核丝核菌,另外8株属于双核丝核菌;经菌丝融合鉴定、rDNA-ITS区及TEF-1α(translation elongation factor 1-alpha, TEF-1α)序列分析,大多数多核丝核菌属于立枯丝核菌(Rhizoctonia solani)AG-2-1(74％),其他少数分别属于AG-1-IB(16％)、AG-4-HG II(2％)和双核丝核菌AG-A(8％)。温室条件下进行寄主范围致病力测定,各分离物对原寄主都表现出致病力,呈现典型叶腐或茎基腐症状;对其他作物的致病力差异较大。不同融合群(Anastomosis group,AG)的菌株对寄主致病力大小存在差异,AG-2-1致病力最强,只有AG-A对叶部没有致病力。AG-2-1对寄主叶部的致病力和对茎基部的致病力呈显著正相关,AG-1-IB对寄主叶部的致病力和对茎基部的致病力无显著相关性。     

施钙对间作遮荫条件下花生生育后期光合特性、糖代谢及产量的影响

于2016-2017年以花育25号为材料,在花生单作和间作条件下,设置施钙和不施钙处理,研究钙肥对单作花生、间作中间行和间作边行花生的植株性状、功能叶生育后期光合特性、糖代谢酶活性及产量的影响。结果表明,施用钙肥降低了花生主茎高和侧枝长,增加了花生分枝数、主茎节数,提高了叶片叶绿素含量、光合速率、蔗糖含量及蔗糖代谢相关酶活性;单作和间作花生荚果产量平均增产397.2 kg/hm^2,平均增产率19.9%。相同施钙水平下,越靠近玉米行的间作边行花生受遮荫影响越大,其主茎高、侧枝长较大,蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)活性等生理指标低于单作花生。与单作不施钙比较,施钙显著增加了间作花生叶绿素含量,使其光合特性、蔗糖含量、SS、SPS酶活性无显著降低,降低了间作花生的减产幅度。本试验条件下,每公顷施用钙肥300kg可部分缓解间作遮荫对花生的不利影响。     

泰和乌鸡肉营养成分特征分析

泰和乌鸡因其药食同源而闻名天下,为探讨泰和乌鸡营养成分在性别之间和与其他鸡种间的差别与优势,测试分析了乌鸡的公鸡-阉鸡-母鸡之间、林下散养-笼养之间和散养乌鸡-散养小黄鸡之间鸡肉中营养成分的区别,结果表明:林下散养乌鸡具有高氨基酸、适中蛋白质和低脂肪特征,乌鸡肉中富含硒和锌、铁、锰等微量元素,不饱和脂肪酸含量高于饱和脂肪酸;呈味氨基酸含量公鸡高于母鸡,乌鸡高于小黄鸡。