罗顿豆与3种多年生禾本科牧草的混播

在湘南红壤丘陵区以南非马唐(Digitaria smutsii)、索兰德狗尾草(Sorander bristlegrass)、扁穗牛鞭草(Hemarthria compressa)分别与罗顿豆(Lotononis bainesii)进行混播试验,以探明其最佳混播组合及其混播比率与混播方式。结果表明:本试验中,隔1行罗顿豆种2行南非马唐处理和隔2行罗顿豆种1行南非马唐处理是产草总量潜力较高的栽种模式,散栽50%罗顿豆和撒播50%索兰德狗尾草处理是粗蛋白产量潜力最高的栽种模式;罗顿豆与3种多年生禾本科牧草混播,相同处理下不同禾本科牧草总产量和粗蛋白产量差异明显,当罗顿豆和禾本科牧草用量各为正常用量的50%时,同一禾本科牧草条播与撒播处理对产草总量无显著影响;与禾本科牧草单播相比,次年相应混播处理均能提高牧草总产量和粗蛋白产量。     

Production of plantlets from tissue cultures of Lotononis,a southern African veld legume1

Abstract

A simple procedure is described for the production of large numbers of rooted plantlets from callus cultures of Lotononis bainesii Baker. Highest frequency of shoots was obtained from somatic embryos formed in initiation cultures on Murashige & Skoog medium plus 1 mg/l benzylaminopurine plus 1 mg/l naphthaleneacetic acid. The somatic embryos from these initiation cultures were transferred to media containing 0,5,10 or 20 mg/l isopentenyladenine or 0,1 or 5,0 mg/l kinetin (1,8 to 3,1 shoots per culture) where they re‐callused and produced shoots. All shoots obtained from the cultures on media containing 0,5, 10 or 20 mg/l isopentenyladenine or 0,1 mg/l kinetin were rooted; 35 % of shoots from the cultures on medium containing 5,0 mg/l kinetin were rooted. Rooting of unrooted shoots from other treatments was readily induced on medium containing 0,1 mg/l indoleaceticacid.     

红壤幼龄桔园套种豆科牧草后土壤酸度变化特征

基于2010—2011年开展的幼龄桔园套种豆科牧草对土壤酸度影响试验,以当地常规管理模式为对照,分析了种植圆叶决明和罗顿豆对土壤pH、交换性酸、铝的影响,及其与土壤养分含量的关系,并结合室内培养试验分析豆科牧草影响红壤酸度的主要因素。结果表明,与试验之初相比,套种圆叶决明处理0~20 cm土壤pH升高了0.19个单位,而罗顿豆处理土壤pH无显著变化。与常规模式相比,套种圆叶决明处理0~20 cm和20~40 cm土壤pH分别升高了0.26个和0.39个单位,而0~20 cm土壤交换性酸、铝含量分别降低了1.25 cmol(+)·kg~(-1)和1.35 cmol(+)·kg~(-1),20~40 cm土壤交换性酸、铝均降低了1.07 cmol(+)·kg~(-1)。土壤交换性铝含量与土壤全氮呈显著负相关(P0.05),而土壤全氮与土壤有机质和有效磷均呈极显著正相关(P0.01)。室内培养试验表明,豆科牧草的灰化碱含量和还田量是影响其改良红壤酸度的两个主要因素。可见,在酸性红壤上套种圆叶决明和罗顿豆未加剧表层(0~40cm)土壤酸化,相反套种圆叶决明对红壤酸度具有一定的缓解效果。