Utilization of phosphorus sources of different availability by mycorrhizal and non-mycorrhizal maize

Abstract

The mycorrhizal relationship has interested biologists since its discovery by F r a n k 5. Since that time much study has been devoted to its occurrence and effect upon the associated higher plant. Our understanding of the mycorrhizal relationship is relatively advanced in the case of the ectotrophic mycorrhizas. The status of knowledge about the effect of the endotrophic vesicular-arbuscular mycorrhizae which occur on most crop plants, as well as many trees is, on the other hand, much more restricted. This lack of information is largely accounted for by the difficulty of isolating the vesicular-arbuscular fungi in pure culture. Only B a r r e t t 2 has reported the successful isolation of vesicular-arbuscular fungi (probably Endogone spp.) and the synthesis of mycorrhizae with them. We have successfully repeated B a r r e t t ' s isolation, however, we have consistently failed to obtain infection with the isolates. Evidence by investigators using various types of non-pure inoculum indicates that plants benefit from infection by the associated vesicular-arbuscular endophyte. This beneficial effect is shown by increased growth and uptake of certain nutrients. The uptake of phosphorus seems to be especially increased.

Growth and mineral nutrition responses of mycorrhizal and non-mycorrhizal cowpea, pigeon pea and groundnut to phosphorus sources of different solubilities

“…These results are in sharp contrast to the observation by Murdoch et al (1967) that treatments with a readily available source of P produced no significant differences in P uptake or dry matter yield between mycorrhizal and nonmycorrhizal maize plants but with RP treatments, they obtained a much higher dry matter yield and P accumulation when plants were mycorrhizal. These workers and others (Hall et al, 1977;Mosse et al 1976) concluded that mycorrhizal plants could utilize rock phosphate fertilizers whereas non-mycorrhizal ones could not.…”

Nutrient Status and Mycorrhizal Enhancement of Water Transport in Soybean

“…The increased growth has been attributed to an enhanced nutrient uptake by the host plant (2,12,15,(18)(19)(20)26). Mycorrhizal plants take up more phosphorus than nonmycorrhizal controls when relatively unavailable sources of phosphorus are supplied to the roots (12,26).…”

“…The increased growth has been attributed to an enhanced nutrient uptake by the host plant (2,12,15,(18)(19)(20)26). Mycorrhizal plants take up more phosphorus than nonmycorrhizal controls when relatively unavailable sources of phosphorus are supplied to the roots (12,26). In most cases the addition of more readily available phosphorus eliminates differences in growth and phosphorus uptake (3,12,13,20,26).…”

“…Mycorrhizal plants take up more phosphorus than nonmycorrhizal controls when relatively unavailable sources of phosphorus are supplied to the roots (12,26). In most cases the addition of more readily available phosphorus eliminates differences in growth and phosphorus uptake (3,12,13,20,26).We have recently shown that VA3 mycorrhizae also decrease the resistance to water transport in whole soybean plants (31). The present study was undertaken to determine where the fungus acts and whether the lowered resistance to water transport can be attributed to increases in the nutrient status of the host brought about by the mycorrhizae.…”

The Effectiveness of Vesicular‐arbuscular Mycorrhizas in Increasing Growth and Phosphorus Uptake of Subterranean Clover From Phosphorus Sources of Different Solubilities

“…Hence comparisons have been based on top yield and phosphorus uptake at a particular rate of application (e.g. Murdoch, Jacobs and Gerdemann 1967;Powell and Daniel, 1978). Moreover in most studies, the rate of application of the insoluble phosphorus sources was inadequate for «|aximum plant growth (for example, Daft and Nicolson, 1966;Powell and Daniel, 1978) This is not a valid comparison of the effect of VA mycorrhizas on the uptake of phosphorus from various sources of different solubilities, because the extent to which VA mycorrhizas increase phosphorus uptake and growth varies with phosphorus application rates (Abbott and Robson, 1977;Barrow, Malajczuk and Shaw 1977).…”