Influence of Three Arbuscular Mycorrhizal Fungi and Phosphorus on Growth and Nutrient Status of Taro

Abstract

Glasshouse and field experiments were conducted with micropropagated (tissue culture) taro plants and germinated corms to determine the arbuscular mycorrhizal dependency of taro. The micropropagated plants (cultivar Laiyu 3) were transplanted in plastic pots (3‐L) containing a mixture of vermiculite:perlite:peat:sand (2:1:1:1) with 0 or 8000 units of inoculum potential (UIP) of Glomus mosseae (Nicol & Gerd) Gerdemann and Trappe, Glomus versiforme (Karsten) Berch or Gigaspora rosea Nicolson & Schenck. Budded corms were planted in clay pots (8.5‐L) containing sterilized sandy loam mixed with 0 or 12,000 UIP of G. mosseae or G. versiforme, and 0 or 5 g Ca₃(PO₄)₂ were added. In a field experiment, budded corms were placed in paper pots (0.5‐L) with sterilized sandy loam mixed with 0 or 4000 UIP of G. mosseae or G. versiforme and then planted directly in the field. Inoculation with AM fungi significantly increased survival rate and growth of tissue culture taro plants, and the contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), copper (Cu), and zinc (Zn), enhanced the formation of corms, numbers of second and third branch corms and corm yield, and enhanced the contents of crude protein, starch, and amino acids in the corms. Phosphorus fertilizer slightly increased plant yield but reduced plant absorption of Cu and Zn and root colonization by the AM fungi. Relative mycorrhizal dependence (RMD) of micropropagated plants was greater than that of corms.

Keywords:

• AM fungi
• taro
• phosphorus
• mycorrhizal dependency
• corms
• micropropated plants

Acknowledgments

We thank Dr. J.S. Wang for her kind gift of micropropagated taro plants, the National Natural Science Foundation of China [GZ015‐11(155) and 39970498], and the Chinese Ministry of Education (Foundation for University Key Teachers) for generous financial support.