Question

Cytoplasmic male sterility in maize is the phenotypic manifestation of the interaction between
(a) Cytoplasmic factors and male fertile nuclear genes
(b) Cytoplasmic factors and male-sterile genes
(c) Mitochondrial and chloroplast genes
(d) Chloroplast genes and nucleus

Answer 1

Extracellular genome and nuclear genome controls male sterility because they have the ability to restore fertility. Nuclear restoration of fertility is an indication of cytoplasmic male sterility.

Complete step by step answer:
As a result of nuclear and mitochondrial interactions, the plant attains partial or total male sterility called cytoplasmic male sterility. Plants with this condition fail to produce functional male gametes. In cytoplasmic male sterility, the manifestation may be controlled by the interaction between nuclear factors and cytoplasmic factors or only by cytoplasmic factors. It is caused due to mutations in the cytoplasmic genes and/or nuclear genes.

Additional information:
- Cytoplasmic male sterility is under the control of mitochondrial or plasmid genomes. This male sterility is inherited from the female plant(maternal), thus it shows non-mendelian inheritance.
- Generally, there are two types of cytoplasms namely normal cytoplasm and sterile cytoplasm. Reciprocal differences are seen in these cytoplasms
- In the production of hybrid maize, cytoplasmic male sterility is an important part. It is attained by the interaction between the cytoplasmic genes and male fertile nuclear genes
- At the starting of the 1950s, the first commercial maize hybrid was discovered by the cytoplasmic male sterility in Texas and named it CMS-T. It eliminated immature pollen-producing bodies.

So, the correct answer is ‘cytoplasmic factors and male fertile nuclear genes’

Note: -It is easy to detect male sterility because this produces a large number of male gametes i.e, pollen grains. Carmine, iodine, and lactophenol are used to assay these pollen grains by using different staining techniques.
-When compared to female sterility, male sterility is more prevalent.