Cucurbit Genetics Cooperative Report 10:45-46 (article 26) 1987
Multiple-Flowering Character in Muskmelon (Cucumis
I. A. Khan, L. F. Lippert, and G. E. Jones
Department of Botany and Plant Sciences, University of California, Riverside,
The expression of multiple flower per node has potential for concentration
of fruit set with ultimate value in once-over harvest and thus reduced harvest
costs. Yield potential and inheritance of multi-pistillate flowering in
cucumber has been thoroughly investigated (recessive major gene, multi-
pistillate, symbol mp), with the goal of circumventing "first-set
fruit" inhibition (2,7). Multiple hermaphroditic flowering evident
in Capsicum sp. has been transferred by interspecific hybridization
with inheritance subsequently characterized as quantitative with some epistatic
interactions (5,6). Muskmelon has several mutations for flower-related traits,
with 13 such mutants listed in the 1986 gene list for muskmelon (1). We
report here the spontaneous occurrence of multiple flowers per node.
The multiple flowering pattern was observed on a single plant of PI 414723,
a monoecious introduction from India. This entry is one of several land
races grown in the Indian subcontinent and locally termed "Phutt,"
which means literally "to split," referring to the extreme longitudinal
splitting of fruits at maturity. We are interested in PI 414723 as a source
of virus resistance. Provvidenti (4) has determined that plants within PI
414723 are immune to strains of zucchini yellow mosaic virus, and Pitrat
and Lecoq (3) report it to be a source of multiple insect and disease resistance.
Preliminary indications are that this material may resist egg mass survival
for root knot nematodes (Mankau, personal communication).
During the process of screening shoot-tip derived plants of PI 414723
in the greenhouse for ZYMV resistance in December 1985, we observed one
plant with multiple pistillate flowers at every node. The number of flowers
per node varied from 2 to 5. Cuttings from the original plant maintained
the multiple- flower trait. However, some branches interrupt the multiple-flowering
expression with nodes of only single flowers. Cutting-derived plants were
grown at 2 field locations in California in 1986. Multiple fruits were set
per node and these were borne to maturity, with a noticeable concentration
of set and maturity.
Reciprocal crosses have been made using both the original plant and derived
cuttings with an andromonoecious commercial cv. Topmark. All Fl's
expressed monoecy, as expected, with nodes containing multiple flowers dispersed
along the runners. A series of greenhouse-grown F1 plants showed
multiple flowering on main runners at early nodes (5-7), at intermediate
nodes (12-14), and again at later nodes (20-24). The remaining nodes either
failed to form flowers or exhibited only single pistillate flowers. Individual
flowers in the multiflowered nodes appeared both axially and terminally.
In Fig. 1, the 3 pistillate flowers are seen terminating a lateral branch
of one of the Fl's. The central, terminal flower is the youngest,
and is smaller in size and later in development compared to the 2 lateral
flowers. Hybrid vigor was evident in fruit size. Additionally, some other
'Topmark' expression such as fruit netting and total soluble solids were
Seeds for F1, F2, and BC generations are available
for field testing in 1987 to permit additional data on expression and inheritance
of multiple flowering in muskmelon.
Figure 1. Multiple flowering in lateral branch F1 (PI 414723
x Topmark) muskmelon.
- Cucurbit Genetics Cooperative. 1986. Gene list of muskmelon (Cucumis melo L.). Report No. 9:111-120.
- Nandgaonkar, A.K, and L.R. Baker. 1981. Inheritance of multi-pistillate
flowering habit in gynoecious pickling cucumber. J. Amer. Soc. Hort.
- Pitrat, M., and H. Lecoq. 1984. Inheritance of zucchini yellow mosaic
virus resistance in Cucumis melo L. Euphytica 33:57-61.
- Provvidenti, R., D. Gonsalves, and H.S. Humaydan. 1984. Occurrence
of zucchini yellow mosaic virus in cucurbits from Connecticut, New York,
Florida, and California. Plant Disease 68:443-446.
- Subramanya, R. 1983. Transfer of genes for multiple flowers from Capsicum
chinense to Capsicum annuum. HortScience 18:747-749.
- Tanksley, S.D., and J. Iglesias-Olivas. 1984. Inheritance and transfer
of multiple-flower character from Capsicum chinense into Capsicum annuum. Euphytica 33:769-777.
- Uzcatequi, N.A., and L.R. Baker. 1979. Effects of multiple-pistillate
flowering on yields of gynoecious pickling cucumbers. J. Amer. Soc. Hort.