Corn (Zea Mays) rusts (Puccinia sorghi, P. Polysora, Physopella zeae). V. Proofs of corn resistance to common rust (P. sorghi)

Abstract

The results with 77 inbred corn lines and 25 hybrids are reported. Inbred lines were obtained from the Instituto de Pesquisas e Experimentação Agropecuárias do Centro-Sul (IPEACS). Hybrids were the same as those used in the 1963-64 National Hybrid variety trials. Several greenhouse and field inoculation tests were conducted utilizing a urediospore mixture containing 13 P. sorghi races. Twelve inbred lines and 8 hybrids were found to be resistant. A severe natural infection in the field with Helminthosporium turcicum occurred and was evaluated. The author suggests that the presence of rust resistance factors might be related to the degree of homozygosity and specific combination capacity in inbread lines and the productive capacity of the hybrids.