Breeding in sapota

Breeding in sapota, various germplasm resources available across india, breeding objectives in sapota. Hybridization in sapota

1. BREEDING IN SAPOTA Lecture #9

2. Sapota : Achras zapota ., Family : Sapotaceae Chromosome number is 2n=2x=26.

3. IMPORTANT CHARACTERS: Flowers show “Protogyny” Pollination is done by means of Wind. Stigma grows of out of flowers 2 days before Anthesis. Floral Biology: Flowers open between 4-4.30 a.m. Anthers dehisce between 8-10 p.m. The flowers keep fresh for nearly two days. The stigma is found to be receptive two days before opening and continues to be like that up to 12hours after opening. Peak receptivity is between 8-10 a.m. The total time taken from fruit set to maturity is 10-12 months under North Indian Conditions but in South Indian conditions it takes only 4-5 months.

4. Hybridization Procedure: Flowers are emasculated and bagged before 4- 5 PM and well before the stigma protrudes out of the bud . The actual procedure consists of making a circular incision around the flower bud with sharp knife or blade, so that 2/3 of the upper floral cup is removed including the portions of calyx, corolla and epipetalous stamens. The style is left in position in remaining 1/3rd of the floral cup. Stamens from male parent , which should shed their pollen in the early hours of next day, are collected in the previous day evening and kept over night in a petridish. These are used to pollinate the receptive stigma of the emasculated flower between 8-10 AM in the next day.

5. Breeding objectives The main emphasis on breeding of Sapota are to develop dwarf stature trees with precocity in bearing, high yield and high keeping quality of less seeded fruits with less latex.

6. Breeding methods: Clonal Selection: Number of varieties like Cricket Ball, Kirthi Barthi , oval, Thagarampudi , Badami , Baramasi and Guthi exhibit natural variability. Exploration of this natural variability by clonal selection is an accepted method of breeding in Sapota. Cricket Ball

7. CO.2 : developed at Tamilnadu Agricultural university, Coimbatore is a clonal selection from Baramasi . It is a high yielder; seeds are less in number and small sized (2-3) PKM.1 : developed at Horticultural College & Research institute, Periykulam (TNAU) is also a clonal selection from Guthi . It is a dwarf, high yielding (3600 fruits/tree/year ), almost bearing throughout year.

8. PKM – 4: a clonal selection from open pollinated seed of PKM – 1. It has spindle shaped fruits suitable for dry flakes production. Pulp is attractive with light pinkish honey brown color, crisp and sweet flesh (TSS 24°brix).

9. Hybridization Tamil Nadu Agricultural University, Coimbatore has developed four hybrids so far. Co.1 : It is a hybrid between Cricket Ball X Oval . The fruits are long oval (egg shaped), medium in size with a mean fruit weight of 125g. The flesh is granular in texture and reddish brown in color, taste being very sweet with a TSS of 18°Brix . Co.3 : It is hybrid between Cricket Ball X Vavivalasa . Fruits are oblong - ovate in shape. Pleasantly flavored, very sweet with a T.S.S of 24.2°. The stature of the tree is more upright and compact, suitable for high density planting at a spacing of 5-6 m either way instead of the conventional spacing of 8mx8m.

10. PKM.2 : It is a hybrid between “ Guthi X Kirthi Barthi ” A high yielder with a performance of 1500 to 2000 fruits per tree per year. PKM. 3 : It is a hybrid between Guthi X Cricket Ball . It has vertical growth habit and hence lends itself for high density planting . Trees bear big sized fruits with oval shape and have cluster-bearing habit . DHS:1 : A hybrid between “Kalipatti X Criket Ball” developed at UAS, Dharwad. The fruits are very sweet having a soft, granular and mellowing flesh with a TSS of 26°brix.

11. The color of the pulp is light orange. The mean fruit weight is 150g. DHS.2: It is also a hybrid between “Kalipatti X Cricket Ball” . The fruits are sweet with a TSS of 23 ° brix having a light orange brown pulp, which is soft, granular and mellowing. The mean fruit weight is 180g.

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