Durable resistance to two leaf blights in two maize inbred lines

Area of Science:

• Plant pathology
• Agronomy
• Genetics

Background:

• Leaf blights caused by Setosphaeria turcica and Drechslera maydis are significant threats to maize production.
• Durable resistance is crucial for sustainable agriculture, minimizing crop losses and reducing the need for chemical interventions.

Purpose of the Study:

• To determine if durable resistance operates in maize inbred lines CM104 and CM105 against S. turcica and D. maydis.
• To assess the longevity of resistance in these maize lines over extended periods.

Main Methods:

• Analysis of 16 and 14 years of disease intensity data for maize inbred lines CM104 and CM105, respectively.
• Utilized linear regression to estimate the regression coefficient of mean disease intensity against years of testing.
• Assessed statistical significance of the regression coefficient to determine resistance durability.

Main Results:

• The regression coefficients for both Turcicum Leaf Blight and Maydis Leaf Blight were not significantly different from zero.
• This indicates that the resistance observed in CM104 and CM105 remained stable over the testing periods.
• The durable resistance is governed by additive gene action, suggesting predictable inheritance patterns.

Conclusions:

• Maize inbred lines CM104 and CM105 possess durable resistance to S. turcica and D. maydis.
• This resistance is heritable and can be effectively transferred to hybrid progenies.
• These findings support the use of these inbred lines for developing resistant maize hybrids.