Cucurbit Genetics Cooperative Report 17:101 (article 30) 1994
A New Morphological Marker in Watermelon, Juvenile Albino (ja)
Xingping Zhang and bill Rhodes
Horticulture Department, Box 340375, Clemson University, Clemson, Sc 29634-0375
In 1992, a new morphological variant, which we name "juvenile albino" (ja) was observed in two populations - selfed 'Dixilee' and an F2 population of G17AB (ms ms) x 'Dixilee'. To our knowledge, this variant has not been documented previously (1). The cotyledon is yellowish when the seedlings emerge from the soil and gradually become greenish-yellow. However, the hypocotyl of the variant remains pure white for a longer time. The shoot, especially the shoot tip, tendrils, male and female flower buds on the main shoot, and new young leaves are all white. Albino leaves gradually become green, and the margin of the leaf remains albino for a much longer time than the interior of the leaf. Surprisingly, the young leaves and flower buds on the secondary branch are not as white as those on the main shoot (Fig. 1). Growth is much slower than normal in the seedling stage, but increases as the plant matures.
Normal pollen and fruits et occur on all branches. The gene affects leaf, tendrils, shoot and flower, as well as rind color. Some portions of the fruit rind are unevenly changed to yellow (Fig. 2). Flesh color is normal. Soluble solids content varied in a few fruit from 9.2-12.8%.
The segregation of normal: juvenile albino in the two popular ions, selfed 'Dixilee' and F2 (G17AB) ms ms x 'Dixilee') was 23.8 and 34:11, respectively. Some of the ja variants in the F2 population were selfed. The F1 population from the cross between the breeding line JX-91 and juvenile albino were all normal. Preliminary results suggest that the juvenile albino may be controlled by a single recessive gene. Families are being developed for analysis of larger populations. Improvement of existing lines and transfer of the gene to other lines is underway. The value of the gene in hybrid seed production will be assessed.
- Henderson, Warren R. 1991. Gene list for watermelon. Cucurbit Genetics Coop. Rpt. 14:129-137.