Inheritance of Early Stomatal Closure Trait in Soybean: Ellis × N09-13890 Population

Area of Science:

• Plant physiology
• Crop science
• Genetics

Background:

• Drought stress significantly reduces soybean yield and growth.
• Selecting drought-adapted soybean genotypes is crucial for mitigating yield losses.
• Early stomatal closure is a vital trait for water-use efficiency under drought.

Purpose of the Study:

• To investigate the inheritance of early stomatal closure in soybean (Glycine max L. Merr.).
• To identify soybean genotypes with varying thresholds for stomatal closure under water-deficit stress.

Main Methods:

• Utilized a population of recombinant inbred lines (RILs) from a cross between N09-13890 and Ellis.
• Conducted a dry-down experiment under controlled conditions to impose progressive water-deficit stress.
• Measured the fraction of transpirable soil water (FTSW) at which transpiration declines.

Main Results:

• Significant variation in FTSW thresholds for stomatal closure was observed among 30 soybean lines, ranging from 0.18 to 0.80.
• Approximately 65% of the RILs exhibited FTSW thresholds between 0.41 and 0.80.
• Results indicate a high level of heritability for the early stomatal closure trait in soybean progeny.

Conclusions:

• Early stomatal closure is a heritable trait in soybeans, valuable for breeding programs.
• Identifying genotypes with superior stomatal closure mechanisms can enhance drought adaptation.
• This research provides a basis for developing soybean cultivars suited for arid and semi-arid regions.