生草栽培对柑桔丛枝茵根形成及果实品质的影响

试验以枳砧锦橙(CitrussinensisOsbeck.)初结果树为试材。试验设4个处理,分别为柑桔园间作百喜草(Bahiagrass)(PaspalumnotaturnFlugge)、白三叶草(Whiteclover)(TrifoliumrepensL.)、紫花苜蓿(Alfalfa)(MedicagosativaL.)和多年生黑麦草(Perennialryegrass)(LoliumperenneL.),以清耕为对照。单行小区,随机区组排列,3次重复。结果表明,在干旱季节,所有生草处理区都显著改善了根际土壤水分和温度状况,而百喜草和白三叶草生草区土壤丛枝菌根真菌孢子数和柑桔根系菌根侵染率显著高于清耕区和其它生草区。表明在干旱季节,百喜草和白三叶草生草栽培促进了果园土壤丛枝菌根真菌的生长和柑桔根系菌根的形成,从而促进了柑桔根系对水分和磷素营养的吸收利用。试验结果表明果园管理中宜选择菌根侵染率高的草种如百喜草、白三叶草在柑桔园进行生草栽培,促进柑桔根系菌根形成,改善植株生理代谢,提高果品质量。

Effects of SOD Culture Management in Citrus Orchard on the Arbuscular Mycorrhizal Infection in Citrus Roots and on the Fruit Quality

This experiment was carried out with bearing citrus plants (Citrus sinensis Osbeck.) on trifoliate orange (Poncirus trifoliata) rootstocks. There are 4 treament plots as follows: Sod culture with bahia grass(Paspalum notaturn Flugge), white clover(Trifolium repens L.), alfalfa(Medicago sativa L.)and perennial ryegrass(Lolium perenne L.)respectively, with clean culture as a control of experiment. All the experimental trees were arranged with a randomized block design with three replications per treatment. The results indicated that the water status and temperature condition in the soil of rhizosphere was improved by sod culture in drought seasons. The number of AM spores and the AM infection rate in citrus roots in bahia grass and white clover sod plot were significantly greater than that in the clean culture plots and other treatment plots. So it was evident that the bahia grass and white clover roots promoted the growth of AM fungi in the soil and AM formation of citrus roots. Under drought stress, high percentage of AM infection of citrus trees in the bahia grass and white clover sod plot was responsible for the increased water and phosphate uptake. It was also suggested a sod culture system of soil management in orchard, utilization of grass with high percentage of AM infection such as bahia grass and white clover, which can enhance the development of fruit and high quality by promoting good formation of AM in the roots and improving the metabolism of nutrition during the drought seasons.