Duplicated phosphoglucose isomerase genes in avocado

Area of Science:

• Plant genetics
• Biochemistry
• Horticulture

Background:

• Avocado (Persea americana) cultivar identification and breeding rely on understanding genetic markers.
• Phosphoglucose isomerase (PGI) is an enzyme involved in carbohydrate metabolism with potential as a genetic marker.

Purpose of the Study:

• To identify and characterize phosphoglucose isomerase (PGI) isozymes in avocado cultivars.
• To assess the utility of PGI isozymic variability for avocado cultivar identification and breeding.

Main Methods:

• Starch gel electrophoresis was used to assay PGI isozymes in various avocado cultivars.
• Genetic analysis involved comparing PGI zymograms from somatic and pollen tissues.
• Mendelian analysis of progeny from selfed avocado trees was performed.

Main Results:

• Three PGI genes were identified: Pgi-I (plastid isozyme) and two independently assorting loci, Pgi-2 and Pgi-3 (cytosolic isozymes).
• Pgi-I was found to be monomorphic, while Pgi-2 and Pgi-3 exhibited variability.
• Distinct PGI zymogram patterns were observed among different avocado cultivars.

Conclusions:

• The identified PGI isozymes provide a genetic basis for distinguishing avocado cultivars.
• PGI isozymic analysis is a reliable method for differentiating hybrid and selfed progeny in avocado breeding programs.
• This research contributes to marker-assisted selection in avocado improvement.