Conservation of Picrorrhiza kurroa with arbuscular mycorrhizal fungi: An endangered and highly economic medicinal herb of Himalaya

Abstract

Arbuscular mycorrhizal (AM) fungi are prevalent from arctic to tropics in most agricultural and natural ecosystems, play an important role in the conservation of some valuable medicinal plants. Picrorrhiza kurroa Royle ex Benth is distinguished endangered medicinal herb, naturally distributed in alpine and sub-alpine region of Himalayas. In present investigation, spores density of AM fungi along root colonization were studied from the rhizospheric soils of P. kurroa collected from different locations of Himachal Pradesh. Highest spore number (60) was found in the soil samples collected from forest nursery Rajkunda while AM root space colonization was highest in the samples of forest nursery Devidhar. The biodiversity of AM fungi was studied; the number of AM species was also highest in these two forest nursery samples. Funneliformis mosseae and Acaulospora laevis were dominant species associated with P. kurroa. After mass multiplication of F. mosseae and A. laevis, bioinoculation experiment was performed on Picrorrhiza kurroa seedlings for the biomass production and nutrient uptake analysis. Seedlings were inoculated with single and in combined mycorrhizal treatments with different combinations of farmyard manure and vermicompost. All inoculated seedlings showed significant biomass production than control seedlings. Root length (8.7cm), fresh and dry biomass was observed to be maximum in the plants inoculated with F. mosseae and vermicompost @ 10t ha−1 while percent AM root colonization was highest (60.33) in the roots of plants inoculated with F. mosseae plus A. laevis with vermicompost @10t ha−1. The phosphorus content was more in seedlings inoculated with consortium of two native AM fungi followed by F. mosseae and A. laevis, separately. In overall, consortium of native AM fungi i.e. F. mosseae and A. laevis was found to be best for the conservation of the P. kurroa in the presence of vermicompost and FYM, respectively.