粤紫萁离体再生技术研究

In vitro regeneration of Osmunda mildei

粤紫萁(Osmunda mildei)为新近形成的自然杂交种,其分布区狭窄、种群个体数量少、有性繁殖能力极低。该文以孢子为外植体,以MS、3/4MS、1/2MS和1/4MS为基本培养基,探讨不同生长调节剂对粤紫萁孢子萌发、原叶体增殖和孢子体形成的影响。结果表明:粤紫萁孢子中极少的可育孢子在植物生长调节剂的作用下,能够萌发并发育形成原叶体;原叶体生长及增殖的最适组合为1/2MS+1.0 mg·L^(-1)6-BA+0.05 mg·L^(-1) NAA和1/2MS+1.0 mg·L^(-1)6-BA+0.5 mg·L^(-1) IBA;在1/4MS基本培养基中,原叶体增殖的同时生长发育完善,形成正常的幼孢子体,形成率达83.49%;孢子体最佳生根配方为MS+0.5 mg·L^(-1) IBA;组培苗在河沙∶黄土∶腐殖质=1∶1∶3的栽培基质中成活率在98%以上,且生长旺盛。综上结果,该研究为粤紫萁的人工繁育及其资源保护以及其他濒危蕨类植物的人工保育提供了参考。

Osmunda mildea is a recently formed natural hybrid species with a narrow distribution area.The number of the population is very small,and its sexual reproduction is extremely low.Using spores as explants,we investigated the effects of basic media(MS,3/4 MS,1/2 MS and 1/4 MS)and different plant growth regulators(PGRs)on spores germination,prothallium proliferation and sporophyte formation.The results were as follows:Extremely few fertile spores of O.mildea could germinate and develop into prothallus in effect of plant growth regulators;The optimal PGRs combinations of prothallus growth and proliferation were 1/2MS+1.0 mg·L^(-1)6-BA+0.05 mg·L^(-1) NAA and 1/2MS+1.0 mg·L^(-1)6-BA+0.5 mg·L^(-1) IBA;In the 1/4MS with no PGR medium,prothallus were well developed with the proliferation,and the young sporophyte seedling formatted,the formation of scale was 83.49%;The best rooting PGR concentration for young sporophyte was MS+0.5 mg·L^(-1) IBA;In loess∶river sand∶humus=1∶1∶3 cultivation matrix was the best,the survival rate was more than 98%,and the seedlings thrived.This study is great significance to the artificial breeding and conservation of O.mildea,and also provides reference to the artificial conservation of other endangered fern species.