Abstracts |
Genetic variation and mycorrhiza play important roles in plant uptake of phosphorus (P). A pot experiment was conducted using wheat (Triticum aestivum cv. PBW-34), rye (Secale cereale cv. R-308) and triticale (Triticale octoploide cv. DT-46), a hybrid of wheat and rye, to examine the genetic variation in the degree of arbuscular mycorrhizal (AM) infection and its heritability from parents (wheat and rye) to their progeny (triticale). The soil used for pot culture was low in available P (7.8 mg P/kg soil). Inoculation with AM fungi showed a significant increase in extent of root colonization for all three cereals (average 70%) compared with their performance without AM (average 19.1%). However, among the three cereals, this increase was significantly greatest in rye, while it did not differ significantly between wheat and triticale. Mycorrhizal infection resulted in 1.6-, 1.7-, and 1.8-fold increases in shoot, root and total plant dry matter, respectively, compared with the uninoculated treatment. Among the three cereals, rye recorded the maximum shoot, root and total plant dry mass and P content with AM inoculation. The P uptake by wheat, rye, and triticale was 10, 64 and 35%, respectively, higher with rather than without mycorrhizal infection. Rye was most responsive to AM inoculation, with mycorrhizal dependency of 193%. Rye showed an increase in P utilization efficiency (PUE) without AM inoculation, while the PUE of triticale was intermediate between wheat and rye. High efficiency of AM symbiosis in terms of P uptake existed in rye and most of these traits in triticale seem to be inherited from wheat rather than rye. |