Methods for enhancing the production and consumer traits of plants

A method for producing a hybrid maize plant, plant material or seed that has an enhanced vigor in comparison with a conventional mutant shrunken-2 hybrid maize plant, plant material or seed and one or more additional desirable traits, including an enhanced ability to retain sugar over a period of time following a prime eating stage thereof, in comparison with a conventional mutant sugary-1 or shrunken-2i hybrid maize plant, plant material or seed, consisting of the following steps:

• (a) identifying an inbred maize plant line that includes one or more desired mutant endosperm alleles in its genome, singly or in combination, optionally using one or more molecular markers, wherein the mutant endosperm alleles are sugary-1 (su1), sugary enhancer-1 (se1) or shrunken-2 (sh2), or any combinations thereof;
• (b) constructing one or more female near isogenic maize plant lines having a desired genotype for use as a genetic background in a combination with a female parental maize plant line that includes a shrunken-2i (sh2-i) mutant endosperm allele in its genome;
• (c) incorporating a shrunken-2i mutant endosperm allele into the genome of the female near isogenic maize plant line having the desired genetic background of step (b), optionally using one or more molecular markers, wherein the desired genetic background is su1su1 se1se1 sh2sh2 or su1su1 se1se1;
• (d) selecting a female converted near isogenic maize plant line of step (c) having a shrunken-2i mutant endosperm allele incorporated into the genetic background of step (c), wherein the female converted near isogenic maize plant line includes an endosperm allelic combination of su1su1 se1 se1 sh2-i sh2-i;
• (e) crossing the selected female converted near isogenic maize plant line of step (d) with a male maize plant line that does not include a shrunken-2i mutant endosperm allele in its genome, and that includes a triple homozygous recessive endosperm allelic combination in its genome, wherein such triple homozygous recessive endosperm allelic combination is su1su1 se1se1 sh2sh2;
• (f) optionally, examining a physical appearance of seeds or kernels produced by the maize plants of step (d), step (e), or both step (d) and step (e), for characteristics including smoothness, fullness or relative weight, or a combination thereof;
• (g) optionally, conducting one or more warm, cold, or both warm and cold, laboratory, field, or laboratory and field, germinations of seeds or kernels produced by the maize plants of step (d), step (e), or both step (d) and step (e), to verify that such seeds or kernels have one or more desired consumer or grower traits, or a combination thereof;
• and
• (h) optionally, conducting one or more organoleptic taste, pericarp tenderness or other tests on maize plants, or plant parts, or a combination thereof, that are grown from seeds or kernels produced by the maize plants of step (d), step (e), or both step (d) and step (e), to determine their taste, pericarp tenderness or other organoleptic characteristics, or a combination thereof;
• wherein the hybrid maize plant, plant material or seed has an enhanced vigor in comparison with a conventional mutant shrunken-2 hybrid maize plant, plant material or seed;
• and wherein the hybrid maize plant, plant material or seed has an enhanced ability to retain sugar over a period of time following a prime eating stage thereof in comparison with a conventional mutant sugary-1 or shrunken-2i hybrid maize plant, plant material or seed.