In vitro selection for methomyl resistance in CMS-T maize

Area of Science:

• Plant breeding and genetics
• Agricultural entomology
• Biotechnology

Background:

• Texas (T) type of cytoplasmic male sterility (CMS-T) in maize is susceptible to methomyl insecticide.
• In vitro selection offers a method to develop resistant plant lines.

Purpose of the Study:

• To obtain and characterize methomyl-resistant maize plants from CMS-T lines.
• To investigate the inheritance and associated traits of methomyl resistance.

Main Methods:

• In vitro selection of maize callus using methomyl.
• Regeneration of plants from selected callus.
• Field testing of resistant plants and their progeny.
• Assessment of mitochondrial physiology and T-toxin resistance.

Main Results:

• Methomyl-resistant plants were obtained through both in vitro selection and non-selection methods.
• Resistance was maternally inherited and linked to reversion to male fertility.
• Resistant plants also showed resistance to T-toxin and altered mitochondrial physiology.
• Prolonged plant tissue culture increased the frequency of resistance.

Conclusions:

• Methomyl selection is effective for generating cytoplasmic mutants in maize.
• This system aids in developing improved sweet corn lines and understanding cytoplasmic inheritance.
• The study highlights the influence of nuclear background and culture conditions on cytoplasmic mutation generation.