Cucurbit Genetics Cooperative Report 3:63 (article 35) 1980
Taxonomic Position of Dosakaya (Cucumis sp.) - The Acid Melon of India
V. A. Parthasarathy1 and C. N. Sambandam2
of Horticulture, Faculty of Agriculture, Annamalai University,
Tamil Nadu - 608 101, India
Dosakaya is a cultivated Cucumis grown in Andhra
Pradesh, for its sour fruits which are used in many culinary
preparations ranging from curries to pickles. According
to Rao (4), Dosakaya types are C. sativus. There
are no reports available on the systematic status of Dosakaya,
but Kailasam (2) reported that Dosakaya was crossable with
both C. melo and C. sativus. However,
his studies lacked cytological evidence. With a view to
ascertatin the systematic position of Dosakaya, the present
studies were undertaken.
Seeds of ten Dosakaya types were used in the study. Counts
of somatic chromosomes were made from root tip cells following
the procedure of Roy (5) using propiono-orcein stain. To
ascertain the compatibility with other Cucuis species, reciprocal
crosses were made with Cucumis metuliferus, C. anguria,
C. longipes, C. zeyheri, C. myriocarpus, C. dipsaceus, and
C. melo. The success of the cross was determined by
the per cent of fruit set in crosses, number of developed
seeds in crossed fruits, per cent of pollen fertility and
viability in F1. Meiotic studies were carried out in the
pollen mother cells of F1 plants to study the behavior of
chromosomes during diakinesis.
Examination of many metaphase plates of root tip cells
revealed the chromosome number of 2n=24 in all Dosakaya
types studied. The crosses revealed that each Dosakaya type
studied was crossable with only C. melo. Fruit
set was nil in crosses with other species. However, crosses
with C. melo were successful only when C. melo
was used as staminate parent. This failure may be due to
the fact that the C. melo cultivar (Annamalai)
used in the study was an andromonoecious type, and the mutilation
due to emasculation might have caused the failure of fruit
The results clearly show that the fruit set, mean seed
number, seed germination, and F1 pollen fertility and viability
of crosses between Dosakaya types and C. melo were
well comparable to that of selfing, thus indicating the
free crossability of Dosakaya types with C. melo.
The presence of 24 somatic chromosomes and free compatability
with C. melo as revealed by normal bivalent formation
in all the F1s indicate that Dosakaya is C. melo
(2n=24) and not C. sativus (2n = 14). Kailasam
(2) reported that Dosakaya is crossable with both C.
sativus and C. melo, but recently, Parthasarathy
and Sampathkumar (3) reported that the material used as
C. sativus (cv. Vellari) by Kailasam was actually
C. melo. Hence, Kailasam had used Vellari, a cultivar
of C. melo, erroneously as C. sativus.
- Ganesan, J. 1971. Some studies on six muskmelon varieties
with particular reference to plant characters, floral
biology, natural crossing and fruit characters. M.Sc.
(Ag.) Thesis, Annamalai Univ. 183 pp.
- Kailasam, M. 1972. Some studies on Dosakaya with particular
reference to its relationship with muskmelon (Cucumis
melo L.) and cucumber (C. sativus L.). M.Sc.
(Ag.) Thesis, Annamalai Univ. 63 pp.
- Parthasarathy, V. A. and R. Sampathkumar. 1979. Kayo-morphological
studies on Cucumis sp. cv. Vellari. Curr.
Res. 8: 175-176.
- Rao, P. V. S. 1932. A note on cucumber cultivation in
the Ganjam District. Madras Agric. J. 20:3.
1 Present address: Scientist S-1 (Horticulture), ICAR Res. Complex for NEH Region, Nongrim Hills, Shillong - 793 003, India. The senior author thanks ICAR for the award of a senior fellowship to him.
2 Research Scholar (Horticulture) and Dean, Faculty of Agriculture, respectively.