EFFECT OF GENOTYPE, ENVIRONMENT AND HUMIC ACID ON THE IN VITRO CULTURE OF WHEAT ANTHERS

Abstract

The in vitro anther culture is a useful tool for wheat (Triticum aestivum L.) breeding. Using this methodology makes possible to generate isogenic lines in an inexpensive and faster way than by conventional breeding methods, since it allows the isolation of agronomic recessive homozygous plants and to fix traits in the progeny from hybrids exhibiting the advantageous traits. We investigated the embryogenic responses of anthers derived from crosses among twelve russian Winter-wheat lines (non-responsive to in vitro anther culture), and two Spring-varieties that responded positively. Among the offspring plants, lines with a positive response were found thus demonstrating that in vitro anther culture response is a genetically controlled trait. The effect of environmental conditions on donor plants affected the on in vitro anther responses. Anthers from open field-grown plants (5-25 °C) showed a better embryogenic calli formation (two fold increase) and better green plant regeneration than anthers from greenhouse-grown donor plants (7-35 °C). The applications of three chemicals (Q-2000™, Maxi-Grow™ and Humigen™) to donor-plant spikes revealed that the plants treated with humic acid at 3.5 mL L^-1, increased the embryogenic callus formation (three to five times) compared to the control. A positive correlation between leaf width vs. fertility of regenerated plants was found in seven out of the eight lines tested; thus, leaf width could be used as a morphological marker for haplody or dihaploidy.