Variation in cassava germplasm for tolerance to post-harvest physiological deterioration

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Post-harvest physiological deterioration (PPD) significantly impacts cassava storage and utilization.
• Developing cassava varieties with inherent PPD tolerance is crucial for reducing losses.
• Understanding the genetic basis of PPD tolerance is essential for effective breeding programs.

Purpose of the Study:

• To estimate genetic parameters for PPD tolerance in cassava.
• To identify stable sources of PPD tolerance among cassava accessions.
• To evaluate the potential for genetic gain in breeding for PPD tolerance.

Main Methods:

• Evaluated PPD tolerance in 418 cassava accessions across four experiments.
• Quantified tolerance using the area under the PPD-progress curve (AUP-PPD).
• Employed residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) for genetic analysis, including stability (Si), adaptability (Ai), and joint analysis (Zi).

Main Results:

• Significant genotype (G) x environment (E) interaction and genotypic variance were observed for PPD tolerance.
• High individual broad-sense heritability (hg(2)=0.38) and average heritability (hmg(2)=0.52) indicated strong genetic control.
• Nineteen cassava accessions showed consistent high performance across multiple stability and adaptability parameters, yielding substantial genetic gain potential.

Conclusions:

• Cassava germplasm exhibits significant variability for PPD tolerance.
• The identified accessions possess high genetic potential for developing PPD-tolerant commercial varieties.
• Breeding strategies focusing on stability and adaptability can effectively enhance PPD tolerance in cassava.