Competitive ability of maize pollen. Intergametophytic effects

Area of Science:

• Plant genetics
• Reproductive biology
• Molecular biology

Background:

• Pollen competitive ability is a key factor in plant reproduction.
• Understanding intergametophytic interactions is crucial for plant breeding.
• The opaque-2 (o2) gene in maize affects kernel characteristics and may influence pollen performance.

Purpose of the Study:

• To investigate intergametophytic influences on pollen competitive ability in maize.
• To determine if the opaque-2 (o2) allele affects pollen performance.
• To quantify the competitive ability of pollen based on genetic makeup.

Main Methods:

• Utilized the pollen mixture technique with genetically marked pollen (o2 and + alleles).
• Cross-pollinated o2o2 female plants with pollen mixtures.
• Analyzed kernel type frequencies along the ear to measure competitive ability via regression coefficients.
• Assessed pollen marker effects by self-pollinating heterozygous o2/+ plants over four generations.

Main Results:

• The opaque-2 (o2) allele-bearing pollen exhibited a slower germination rate compared to the dominant counterpart (+ allele).
• No significant differences in pollen tube growth rate were observed between o2 and + pollen.
• Pollen competitive ability varied depending on the genotype of the competing pollen, confirming intergametophytic interactions.

Conclusions:

• Intergametophytic interactions significantly influence male gametophyte fertilization ability.
• The opaque-2 (o2) allele's effect on germination rate impacts pollen competitiveness.
• These findings necessitate considering pollen genotype interactions in breeding programs for improved fertilization efficiency.