Increasing phosphorus concentration in seed of annual pasture legume species increases herbage and seed yields

Abstract

In glasshouse experiments with low levels of soil applied phosphorus (P), yields of four annual pasture legumes (Medicago polymorpha, Trifolium subterraneum, T. balansae, Ornithopus compressus) increased with increasing P concentration in the seed.In a further experiment, M. polymorpha cv. Serena was grown at the same plant density from seed of two P concentrations and two seed sizes when two levels of finely ground superphosphate were applied to the soil. Higher P concentrations in the seed increased yields of dried tops by about 30% for the first harvest (21 days), 20% for the second harvest (52 days), and 9% at maturity (103 days), and seed yields by 11%. Larger seeds increased yields of dried tops by between 6-46% for the first two harvests but at maturity yields of dried tops and seed were unaffected by seed size. None of the interactions were statistically significant (P > 0.05), except for the first harvest when two interactions (P concentration in the seed x seed size (i.e. P content in seed), and P applied to the soil x P concentration in the seed x seed size) were significant at P < 0.05 level.In a field experiment, Trifolium subterraneum clover seed (two cultivars) of the same size but with two different P concentrations was sown at the same plant density and two levels of granulated (0.2-5 mm) superphosphate were applied to the soil surface. The higher level of superphosphate increased dried herbage yields of the dense clover swards by three-to four-fold 90 and 120 days after sowing. The higher P concentration in the seed increased yields of dried herbage by between 50 to 25%, depending on the level of P applied to the soil and the harvest date.

Phosphorus efficiency and the forms of soil phosphorus utilized by upland rice cultivars

“…Enhanced early growth from seeds of higher P content has also been found in other plant species (Bolland and Paynter, 1990, and references cited therein). High rice seed P content would therefore be advantageous in P deficient soils, allowing early root development independent of soil P supply.…”

Variation in seedling growth of 11 perennial legumes in response to phosphorus supply

“…2c) which supports the results of many other studies. For instance, in annual pasture legumes (Bolland and Paynter 1990) and in 18 wheat genotypes (Liao et al 2008), the relative increase in shoot dry matter due to higher seed P concentrations decreased with increasing P supply to the soil and with plant age. The influence of seed mass on seedling growth decreased with increasing nutrient availability in the soil for 21 species from three woody genera in Australia, indicating that seed mass exert a large influence on seedling performance only in extremely nutrient-impoverished situations (Milberg et al 1998).…”

Mycorrhizal Symbiosis and Plant Reproduction

“…In Abutilon theophrasti, an increase in seed N content improved competitive ability of the offspring (Parrish and Bazzaz 1985). An increase in seed P content can also positively affect the germination, growth or reproductive output of the offspring such as in Campanula (Nuortila et al 2004), Pisum (Austin 1966), in other legumes (Bolland and Paynter 1990), and in Hordeum (Zhang et al 1990). Thus, even when additional P supplied by the mycorrhizal fungus does not result in increased seed number (when seed production is no longer P-limited), significant consequences to the next generation of plants may still result from mycorrhizal infection of the former generation.…”