Pollen fertility studies showed that flowers from the early flowering stage contain more fertile pollen (93.9-97.6 %) than later stage of flowering (68.9%). Pollen fertility percentage indicates development of anther. If the anthers are well-developed, the pollen fertility is expected to be high. The uninucleate stage is optimal for the culture of melon anthers, and these pollen stages appear in flower bud and anther with 4.5-5.0 mm and 1.9-2.0 mm length, respectively, in first week and 3.3-4.3 mm and 1.6-1.8 mm length, respectively, in the second week. This result indicates that flower and anther size reduces with increase in the age of the donor plant. In the early flowering stage, the plant produces larger flowers than at later stages. Among the three polysaccharides, lactose showed good effect on pollen division. The anther cultured in lactose supplemented MS medium produced the highest number of living anther per plate, number of living pollen per anther and dividing pollen per anther. Maltose supplemented MS medium showed moderate performance and sucrose the lowest for all parameters studied.

The most common name used for Cucumis melo L. is melon. Other names include sweet melon, round melon, muskmelon, casaba, cantaloupe and winter melon (Robinson and Decker-Walters, 1997; and Nayar and Singh, 1998). Melon is a member of genus cucumis under the family cucurbitaceae (Mallick and Masui, 1986). It has many uses, such as immature melon used in fresh salad, cooked (soup, curry, stew and stir-fry) and pickle. Mature fruits are eaten fresh as a dessert fruit, canned or used for jam. Melon has a basic chromosome number of 12 and is a diploid species, 2n=24 (Kroon et al., 1979). Spontaneous haploid in melon occurs rarely. Haploid by anther culture can be used for the improvement of melon. It needs to give attention on the improvement of melon developing 1) high quality flesh with disease and insect resistance; 2) shifting to monoecious and gynoecious types for F1 hybrid seed production; 3) novel fruit types to broaden the utilization of melon; 4) novel plant type for home garden; 5) concentrated fruit set once-over harvest and 6) earliness.

The culture of anther in vitro or on an artificial growth media is called anther culture. First successful anther culture was reported by Guha and Maheshwari (1964 and 1966) in Datura innoxia, and has been modified by various workers (Sopory and Munshi, 1996). Nowadays anther culture technique is extensively used in haploid breeding of many economic crops like rice, wheat, maize, barley, potato, Brassica, asparagus, etc. This is a relatively simple and efficient technique for haploid production. Haploid plants have the gametic number of chromosomes. Haploid plants are of special interest to plant breeders because of the possibility of utilizing their chromosome doubled derivatives in breeding programs as inbred lines. The success of anther culture depends on the size of flower buds and the developmental stage (mid-uninucleate to late uninucleate) of pollen grain. At uninucleate stage, microspores are most suitable for the induction of androgenesis. So the present investigation was undertaken to standardize the flower bud size and developmental stage of pollen grain of melon for successful anther culture.

Genetics & Evolution Journal, CEL-I Endonuclease, Heterozygous Mutants, Homozygous Mutants, Biological Processes, Plant Mutants, Solanum Lycopersicon, Microcentrifuge Tubes, Homozygous Plants, Plant Genes, Cross Pollination, Heteroduplex Formation.