The effect of pre-pollination stylar treatments on seedset and pollen transmission at varoius Maize (Zea mays L.) endosperm mutant loci

Aqueous solutions containing various organic compounds (phytic acid; lipase; thiourea; cellulase; a-amylase; quinaldic acid; gibberellic acid; D-methionine; L-methionine; maleic hydrazide; papain) and different solute-osmotic concentration combinations (sucrose at 5, 10, 15, 20, 25 atm; mannitol at 5, 10, 15, 20, 25 atm; NaCl at 10 atm.) were sprayed on the styles (silks) of three heterozygous (Wx wx; Su su; Sh2 sh2) populations at the waxy, sugary-1, and shrunken-2 loci about 2 h before selfmg. Seed number ear “1 and deviations from the genetic ratio of the control at each locus were used as an index of seedset and pollen transmission, respectively. Seedset was not affected by any organic compound at any locus. Increasing osmotic concentrations generally decreased seedset, but the magnitude of the reduction depended on the solute and locus. The transmission of the recessive allele was significantly altered by some organic compounds, but the direction and magnitude depended on the compound and the locus. In general, the transmission of the recessive allele was increased. The effect of the solute-osmotic concentration solutions on pollen transmission was quite inconsistent with the direction and magnitude of any changes depending on the locus, solute, and concentration. The results indicated that pre-pollination stylar application of water does not alter seedset, and the addition of various agents in the water may amplify pollen transmission differences among alleles at specific loci. Therefore, this procedure may be useful in directing and improving the efficiency of pollen genotype selection programs.