In vitro culture of haploid cells of plants {e.g., pollen grains from anther and ovules from ovary) is possible. In vivo technique of haploid production includes the following :
• Androgenesis: Production of haploid plants by development of an egg cell containing male nucleus. The female nucleus is eliminated before fertilisation.
• Gymnogenesis: Production of haploid plant by the development of an unfertilised egg cells because of delayed pollination (through use of abortive pollen pre-exposed to ionising irradiation or using an alien pollen). It is found in interspecific crosses of potato.
• Chemical Treatment: Some chemicals like chloramphenicol and parafluorophenylalanin may induce chromosome elimination in somatic cells or tissues giving rise to haploid.
In 1953, Tulecke successfully produced callus from isolated pollen culture of gymnosperms. This made a hope to raise haploid plants through pollen culture. For the first time Hameya and Hinata (1970) produced tissues from the isolated pollen grains of an angiosperm.
For the first time S.Guha and P.Maheshwari (1964) produced haploid embryos in vitro from isolated anthers of Datura innoxia. Haploid production has immense use in plant breeding and improvement of crop plants. Haploids provide an easier system for induction of mutation. They can be employed for rapid selection of mutants having traits for disease resistance. The Institute of Crop Breeding and Cultivation (China) has developed the high yielding and blast resistant varieties of rice zhonghua No. 8 and zhonghua No. 9 through transfer of desired alien gene.
