Multivariate Analysis Compares and Evaluates Heat Tolerance of Potato Germplasm

Area of Science:

• Agricultural Science
• Plant Physiology
• Genetics

Background:

• High temperatures are a major constraint on potato (Solanum tuberosum L.) yield.
• Traditional methods evaluating heat tolerance based solely on tuber yield are insufficient due to correlations with maturation period.

Purpose of the Study:

• To investigate physiological changes in potato cultivars under heat stress.
• To develop accurate, comprehensive methods for evaluating potato heat tolerance.

Main Methods:

• Screening 93 potato cultivars using an in vitro tuber induction system under heat stress (30 °C) and normal (22 °C) conditions.
• Further ex vitro testing of selected cultivars under prolonged heat stress (35 °C/28 °C day/night).
• Utilizing principal component analysis, correlation, and regression analysis to identify key physiological and yield traits.

Main Results:

• Heat stress significantly reduced tuber yield and number, increased plant height and internode growth rates, and caused membrane damage.
• Heat stress decreased chlorophyll biosynthesis and photosynthetic efficiency due to chloroplast damage.
• Nine traits (plant height growth rate, fourth internode growth rate, chlorophyll b content, photosynthetic rate, stomatal conductance, transpiration rate, tuber number, tuber yield, and cell membrane injury level) were identified as accurate indicators of heat tolerance.

Conclusions:

• A comprehensive evaluation using nine identified traits provides a 100.0% forecast accuracy for potato heat tolerance.
• Cultivars FA, D73, and C132 demonstrated the highest heat tolerance and are suitable for further breeding as heat-resistant varieties.
• This research offers valuable insights into potato physiological responses to heat stress and improved evaluation methodologies for breeding programs.