(i) Endosperm culture: The endosperm nurses the developing zygotic embryo. For the first time Lamp and Mills (1933) grew7 maize endosperm on nutrient medium 10-20 days after pollination. The endosperm proliferated slightly. In 1949, LaRue succeeded to produce callus from immature endosperm. From India, B.M. Johri and S.S. Bhojwani (1965) at the University of Delhi reported and endosperm culture. Some examples of triploid plants raised from endosperm cultures are : Asparagus officinalis, barley (Hordeum vulgare), rice (Oryza sativa), maize (Zea mays), Prunus persica, Pyrus malus, Citrus gradis, sandle plant (Santalum album).
The triploid plants are self-sterile and usually seedles. This characteristic increases edibility of fruits and desirable in plants such as apple, banana, grape, mulberry, mango, watermelon, etc. These are commercially important edible fruits. The triploids of poplar {Populus tremuloides) have better quality pulpwood. Therefore, it is important to the forest industry,
(ii) Anther culture: When anthers of some plants are cultured on suitable medium to produce haploid plants, it is called anther culture. 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.
It is highly useful for the improvement of many crop plants. It is also useful for immediate expression of mutations and quick formation of purelines. This technique was first used in India to produce haploids of Datura. In many plants haploids are also produced by culturing unfertilized ovaries/ovules. In pollen grain culture pollen grains are eseptically removed from the anther and cultured on liquid medium.
