Cucurbit Genetics Cooperative Report 14:8-9 (article 3) 1991
M. Rucinska, K. Niemirowicz-Szcytt and A. Korzeniewska
Department of Genetics and Horticultural Plant Breeding, Warsaw Agricultural University SGGW, 02-766 Warsaw, Poland
A cucumber (Cucumis sativus L.) mutant with yellow stem and leaf petioles was obtained from a highly inbred line of ‘Borszczagowski’ after treatment of the seeds with the mutagen, ethyleneimine (1). It was one of frequent chlorophyll deficient mutations, restricted to cotyledons, stems, leaf petioles and veins.
Inheritance was studied after the mutant plants were self-pollinated several generations to make a stable, mutant inbred line (P2). The mutant was crossed with an inbred line of ‘Borszczagowski’ (P1) to obtain F1, F1 x P1, F1 x P2 and F2. All observed traits of the mutant were compared with P1.
Statistical measurements of 20 mutant plants were analyzed using Student’s t-test. Inheritance studies were run in a greenhouse in the optimum spring to summer seasons, and data analyzed using chi-square.
It was possible to identify mutant plants initially in the cotyledon stage by the cotyledon color, which was yellow at the beginning and gradually becoming cream-like. In the course of growth, further characteristics appeared, such as cream colored stems, leaf petioles and leaf veins. The mutant hypocotyl was half the length of the standard (38 ± 6 to 92 ± 14 mm). Mutant first leaves were slightly narrower (30 ± 5 to 55 ± 10 mm) and more lobed. Mutant plants were considerably shorter (1567 ± 70 to 2660 ± 62 mm) with the same number of internodes (39) as normal. However, internodes were shorter in the mutant (39 ± 8 to 61 ± 7 mm), and it had fewer lateral shoots (14 ± 3 to 24 ± 3). Like the standard, the mutant was monoecious, with similar flowers and fruits. Pollen viability stain using 2% acetocarmine was nearly the same as the initial line (98 to 99%).
On the basis of genetic analysis (Table 1), we concluded that the character of yellow stem and leaf petioles is determined a single recessive gene, designated ys. The gene also appears to cause the plants to be significantly shorter than normal.
Table 1. Inheritance of yellow stem and leaf petioles (ys) .
No. observed |
No. expected |
||||||
Generation |
Normal |
Mutated |
Normal |
Mutated |
Tested ratio |
X² |
P |
| Borszczagowski (P1) | 65 | 0 | 65 | 0 | 1:0 | – | – |
| ys (P2) | 65 | 20 | 0 | 20 | 0:1 | – | – |
| F1 | 80 | 0 | 80 | 0 | 1:0 | – | – |
| F2 | 138 | 50 | 132 | 40 | 3:1 | 1.08 | 0.50 |
| F1 x P1 | 80 | 0 | 80 | 0 | 1:0 | – | – |
| F1 x P2 | 67 | 65 | 66 | 66 | 1:1 | 1.24 | 0.50 |
Figure 1. Comparison of mutant leaf (note cream-like petiole) and normal one (B-line).
Literature Cited
- Kubicki, B. 1983. Induced mutations in cucumber (Cucumis sativus L.). 1. Variability in M1 and M2 generations. Gen. Pol. 21(4): 409-424.