Cucurbit Genetics Cooperative Report 7:41-42 (article
Climacteric and Nonclimacteric Ripening in Cucumis melo
Stephen Kendall and Timothy J. Ng
University of Maryland, College Park, MD 20742
Many diverse fruit types exist among cultivated genotypes of Cucumis melo. Netted muskmelons and honeydews have been
reported to be climacteric, but nonclimacteric genotypes of C.
melo have also been reported (1). In experiments spanning a
3 year period, we have found that 'Golden Beauty Casaba' (GBC)
and C2, a casaba-type breeding line obtained from the Texas A&M
Agricultural Experiment Station, are nonclimacteric in their
ripening behavior. As the presence and degree of the climacteric
may affect storage life, we initiated studies to investigate this
Crosses were made between several genotypes of C. melo.
'Perlita' (PER), a cultivar with good shipping quality, and MD63-
53, a breeding line which lacks shipping quality, were the netted
genotypes. Our experiments had previously shown that MD63-53
undergoes a climacteric prior to fruit abscission whereas PER
experiences the climacteric rise after abscission. Table 1
presents data from an experiment dealing with field-grown melons
harvested at physiological maturity (stem abscission for netted
genotypes, softening of the blossom end for "non-slipping"
genotypes) and stored at 10 C. Internal ethylene concentrations
were determined by embedding hypodermic needles into the cavity
of the fruit and sampling through septa at selected intervals.
These results along with other experiments involving stored
melons under a continuous air flow have confirmed that
nonclimacteric genotypes of C. melo do exist and that
hybrids between climacteric and nonclimacteric types experience a
delayed climacteric when compared to the climacteric parent.
Table 1. Internal ethylene concentrations in
genotypes of Cucumis melo after harvest when stored at 10 C.
Days from anthesis to maturity
Fruit weight (kg)
Internal C2H4 concentration
PER x MD
PER x C2
PER x GBC
MD x PER
MD x C2
zGenotype abbreviations are 'Perlita'(PER), 'Golden Beauty
Casaba'(GBC), and MD63-53(MD).
yThe last ethylene determination for each genotype was made after
optimum horticultural maturity had been achieved.
xEthylene was not present at a detectable level.
These differences in ripening patterns may be attributable to
genetic differences in the fruit tissues, such as have been
reported for ripening mutants of tomato (2). Oxygen availability
to the fruit tissue may also be a factor since fruits of all
nonclimacteric genotypes did not develop a net; the net in
muskmelons is derived from the lenticels during fruit development
and provides a channel for gaseous exchange with the surrounding
atmosphere. Regardless of the physiological mode of action for
this phenomenon, the implications remain that the use of
nonclimacteric genotypes in breeding programs could be a valuable
tool for genetically increasing the storage life of fruits of C. melo.
- Kitamura, T., T. Umemoto, and T. Iwata. 1975. Studies on the
storage of melon fruits. II. Changes in respiration and
ethylene production during ripening with reference to cultivars.
J. Japan. Soc. Hort. Sci. 44:197-203.
- Tigchelaar, E.C., W. B. McGlasson and R.W. Buescher. 1978.
Genetic regulation of tomato fruit ripening. Hort. Sci. 13:508-513.