Plants can be made disease-resistant by:

Heterosis (hybrid vigor) is desirable in vegetatively propagated plants because:

Four inbred lines of maize are crossed. This type of cross is known as:

Arrange the following steps in the correct sequence for breeding a genetically diverse crop variety:
$I -$ Cross-hybridization among the selected parents
$II -$ Testing, release, and commercialization of new cultivars
$III -$ Selection and testing of superior recombinants
$IV -$ Collection of variability
$V -$ Evaluation and selection of parents

Which selection method is used for vegetative propagation in plants?

Consider the following four measures $(1-4)$ that could be taken to successfully grow chickpea in an area where bacterial blight disease is common.
$(1)$ Spray with Bordeaux mixture
$(2)$ Control of the insect vector of the disease pathogen
$(3)$ Use of only disease-free seeds
$(4)$ Use of varieties resistant to the disease
Which two of the above measures can control the disease?