氮磷钾肥配施对潮土花生产量及养分吸收利用的影响

为实现花生科学施肥,采用田间试验研究了氮磷钾配施对花生产量、养分吸收、干物质积累及肥料利用率的影响。结果表明:氮磷钾配施显著增产46.82%,较农户施肥增产7.53%;施氮、磷、钾肥分别增产27.80%、13.56%、21.12%。氮磷钾配施养分积累量较农户施肥分别提高13.30%、36.48%、40.75%,氮、磷、钾肥当季利用率分别为33.39%、15.17%、39.02%。氮磷钾配施(N-90、P_2O_5-120、K_2O-150 kg/hm~2)促进了花生对氮、磷、钾养分的吸收利用,提高了花生产量,可作为潮土区花生高产施肥配方。     

花生化感物质降解菌的筛选、鉴定与降解特性研究

为筛选高效化感物质降解菌,以花生根系分泌物中的化感物质苯甲酸作为唯一碳源,采用富集培养和稀释平板法从连作花生长期定位试验地的健康花生植株根际土壤中筛选高效花生化感物质降解菌,经形态观察、生理生化分析和16S rDNA序列同源性比较以及系统发育分析对降解菌进行鉴定,并通过单因素试验对降解菌进行降解特性研究。结果表明:筛选到的2株高效降解菌分别为木糖氧化无色杆菌(Achromobacter xylosoxidans HJ-2)和硝基还原假单胞菌(Pseudomonas nitroreducens HJ-3)。降解菌HJ-2降解的适宜pH为6.0～9.0,适宜温度为30～45℃,适宜NaCl浓度为0～6%;降解菌HJ-3降解的适宜pH为6.0～8.0,适宜温度为30～35℃,适宜NaCl浓度为0～4%。两株降解菌都能够降解苯乙酮、硬脂酸、棕榈酸、乳酸、3,5-二甲基苯甲醛和丙三醇等化感物质。研究表明,降解菌HJ-2和HJ-3对苯甲酸有显著降解效果,两个菌株均具有广谱降解化感物质的特性,且降解菌HJ-2对不良环境适应能力较强。     

花生EMS诱变体系的探索及突变体鉴定

突变体创制对花生遗传改良和功能基因组学研究具有重要意义。为获得最佳诱变效果，本研究对不同基因型花生品种的EMS诱变条件进行摸索，发现花育22号、花育71、花育9301、狮头企和伏花生的最适诱变浓度分别为0.4%、0.5%、0.3%、0.5%和0.3%。通过对最适EMS浓度诱变处理下苗期芽长、株高、根长及根数目分析，发现5个品种虽然都能正常成苗，但均受到较严重的损伤。在预实验基础上，用浓度为0.4%的EMS溶液处理了大约5000粒花育22号种子，M1及M2世代性状调查显示突变群体表型丰富，出现株高、株型、荚果、籽仁、分枝数、叶形等表型变异株系，表型变异率为12.9%。本研究为花生遗传改良和功能基因组学研究提供了丰富的种质材料。     

红叶甜菜-花生和油葵-花生轮作修复土壤Cd的能力

利用生物量高的经济作物进行轮作，可在加快修复土壤Cd污染进程的同时获得一定的经济效益。本研究在长沙市望城区群力村Cd轻度污染的土壤进行冬季种植红叶甜菜、夏季复种植花生和春末种植油葵、夏季复种植花生的轮作模式试验，探究重金属修复潜力。结果表明：花生、油葵、红叶甜菜各部位Cd富集系数除花生果实外均大于1，对Cd均有较强的富集能力。油葵-花生、红叶甜菜-花生轮作模式种植一季可提取土壤Cd总量分别为40.80 g·hm^-2和53.34 g·hm^-2。红叶甜菜-花生轮作将土壤Cd含量由0.316 mg·kg^-1降至0.286 mg·kg^-1，油葵-花生轮作一季将土壤Cd含量由0.316 mg·kg^-1降至0.283 mg·kg^-1。研究表明，红叶甜菜-花生、油葵-花生轮作模式均对土壤重金属Cd有较好的修复潜力。     

基于电子鼻的花生有害霉菌种类识别及侵染程度定量检测

针对花生霉变传统分析方法操作繁琐、时效性差等不足,该研究拟利用电子鼻气体传感技术建立起花生有害霉菌污染的快速检测方法。辐射灭菌花生籽粒分别接种5种谷物中常见有害霉菌(黄曲霉3.17、黄曲霉3.395 0、寄生曲霉3.395、寄生曲霉3.012 4和赭曲霉3.648 6),并于26℃、80%相对湿度条件下储藏9 d至严重霉变。利用电子鼻气体传感器获取不同储藏时期(0、3、6、9 d)花生样品的整体挥发性气味信息。最后,结合多元统计分析方法对电子鼻传感器响应信号进行特征提取,建立了花生中有害霉菌污染程度的定性定量分析模型。结果显示,主成分分析法(principal component analysis,PCA)可成功区分不同霉菌侵染程度的花生样品,线性判别分析(linear discriminant analysis,LDA)模型对样品不同储藏天数判别的准确率均达到或接近100%。花生中菌落总数的偏最小二乘回归分析(partial least squares regression,PLSR)模型的预测决定系数和预测相对均方根误差分别达到0.814 5和0.244 0 lg(CFU/g)。结果表明,应用电子鼻技术快速检测储藏期间花生霉变状况具有一定可行性,可为利用气味信息实现粮食霉菌污染的在线监测提供理论参考。     

Farmers' irrigation practices in a high rainfall area

Recent droughts in the humid southeastern United States have focused attention on the need for and use of supplemental irrigation. Total annual rainfall amounts are sufficient for most crops in the region. However, erratic distribution of rainfall and the low water-holding capacities of most soils in the region cause frequent drought stresses in many crops. An on-farm study was conducted in southeastern Alabama to evaluate the effects of farmers' irrigation scheduling decisions on soil moisture variations in peanut fields irrigated with center-pivot irrigation systems. The study showed that the way irrigation was practiced in this high rainfall area often caused soil moisture deficit (SMD) level higher than the desired SMD limit during over 20% of the 140-day growing season. This is partially due to farmers' tendency to delay irrigation in anticipation of rainfall which may or may not occur, as rainfall during the growing season is often erratic and local. In contrast SMD in non-irrigated fields was higher than the SMD limit for half of the growing season.Abbreviations SMD soil moisture deficit - ET evapotranspiration - R_eff effective rainfall - WHC water holding capacity     

A review of the nomenclature of the genus Arachis L.

Summary Confusion has arisen with regard to the correct botanical nomenclature for the taxa within the genus Arachis L. This paper discusses the proper usage, as mandated by the International Code of Botanical Nomenclature, of the epithets within the genus. Adherence to the rules described in this paper should reduce the present confusion in the nomenclature of Arachis.Paper number 6080 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27650 (USA).     

Use of ammonia electrode for total nitrogen determination in plants

Abstract

An ammonia electrode was evaluated as a means of determining ammonium concentration in semi‐micro Kjeldahl digests of plant samples. Results of the ammonia electrode determination agreed closely with distillation and titration results. Advantages of the electrode method include speed, precision, increased safety, simplicity and the fact that only a small aliquot of the digest is used.     

不同生育时期乙烯利处理对花生生物量的影响

为了确定花生生产过程中乙烯利的最佳喷施时期及用量,以湘花2008为材料,通过大田试验研究了盛花期和幼果期分别喷施不同浓度的乙烯利对花生生物量的影响。结果表明:盛花期喷施乙烯利会导致植株提前衰老,不利于生物量的形成;幼果期喷施200~500 mg/L乙烯利,可提高整个生育期花生的叶干重和单株荚果产量,有利于花生生物量的形成。