不同基质中番茄菌根苗的培育及其抗南方根结线虫的效果

Effects of different cultivation substrates on the tomato seedling mycorrhization and Meloidogyne incognita infestation under condition of inoculation with arbuscular mycorrhizal fungi

根结线虫病是番茄主要的土传病害,特别是保护地长期种植会加重病害的发生。接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)能提高植物抗根结线虫的能力,促进植株生长发育,减轻病害。本试验旨在评价常用基质配合施用一种生物有机肥对番茄苗生长和菌根定殖的影响,以获得菌根发育良好且生长健壮的菌根苗,并通过盆栽实验验证菌根苗移栽于大棚连作土壤中对南方根结线虫的防治效果。结果表明,栽培于商业基质的番茄苗的株高、茎粗、地上部及根系干重和壮苗指数均显著高于草炭蛭石混合基Rhizophagus intraradices的侵染。草炭蛭石混合基质在培养过程中施加K°适量Hoagland营养液使番茄苗生长发育较好且根内根孢囊霉R.intraradices侵染率达到71%;商业基质培养的番茄苗壮苗指数更高,但侵染率较低(44%)。在草炭蛭石混合基质中接种变形球囊霉Glomus versiforme和根内根孢囊霉R.intraradices及其混合菌种培育的番茄苗对南方根结线虫Meloidogyne incognita的侵染和繁殖均表现出一定的抑制作用。按照单位重量根系进行统计,混合菌种显著降低了根结线虫的根结和卵块数量(分别降低了22.8%和23.5%)。本研究结果表明番茄菌根苗在草炭蛭石混合基质中AMF发育状况优于常用商业基质,在菌根应用中可优先选择;相对于单一接种AMF,混合接种的菌根化苗对南方根结线虫病害的抑制作用更好。

Arbuscular mycorrhizal fungi(AMF)have potential role in the biocontrol of soil-borne diseases,including plant parasitic nematodes,and can improve the growth of plants.The growth of tomato seedlings colonized by AMF in different substrates with or without supplement of commercial biological fertilizer was evaluated.The tomato seedlings inoculated with Rhizophagus intraradices(Ri)were cultivated in two types of substrate,a commercial cultivation medium and the mixture of peat and vermiculite(2:1).The seedlings grown in the commercial substrate showed increase in shoot length,stem diameter,shoot and root dry weights as compared with those in the mixture of vermiculite and peat.However,the application of the biological fertilizer inhibited the colonization of AMF(Ri)in the mixture of peat and vermiculite though the fertilizer enhanced the growth of seedlings.The seedlings in the commercial medium appeared to be higher in health index and lower in Ri colonization(averagely 44%)than those in the mixture of vermiculite and peat(2:1)(colonization rate reached 71%).The effects of tomato seedlings inoculated with Glomus versiforme(Gv),Ri and the mixture of Gv and Ri on Meloidogyne incognita infestation were investigated in the continuous cropping field soil.The tomato seedlings inoculated with AMF showed inhibition to the root-knot nematode in the field soil containing averagely 7.3 second-stage juveniles per gram of soil.The inoculation of the mixture of Gv and Ri demonstrated the greatest control effects and reduced the number of galls and egg masses of the nematode(decreased by 22.8%and 23.5%respectively).