Cucurbit Genetics Cooperative Report 3:24 (article 13) 1980

"Divided Leaf", a Recessive Seedling Marker in Cucumber

A.P.M. den Nijs and H.O. Mackiewicz

Institute for Horticultural Plant Breeding, Wageningen, The Netherlands (first author); Department of Genetics, Research Institute of Vegetable Crops, Reguly, Poland (second author)

A leaf mutant was obtained by Mackiewicz following ethylenimine treatment of several Polish pickling cucumber cultivars. The character seemed t be inherited recessively, but it was not always fully expressed. During a recent stay of Mackiewicz at the IVT in Wageningen we initiated a crossing program to establish the inheritance of the character and to evaluate its potential as a seedling marker for genetic studies.

Description of the mutant. The true leaves are partly or fully divided or dissected, often resulting in compound leaves with 2 to 5 leaflets, depending on the speed of growth. Under optimal growing conditions several leaves of mutant plants may appear normal, but almost all plants can be recognized by the first true leaf. Corollas of both male and female flowers have deep incisions showing 5 to 7 distinct slips. This deviating shape does not depend on the growing conditions, so the few doubtful plants in segregating progenies can always be classified at anthesis. All plants with divided leaves possessed incised corollas, whereas all plants with incised corollas had at least some off-type leaves. We have seen no evidence of recombination of separate genes for the flower and leaf characteristic, so we assume pleiotropy.

Inheritance. Of two seed samples sown at IVT, one (318) produced uniformly mutant plants while the other (319) segregated for the character. Mutant plants were selfed and crossed amongst each other and with normal segregants as well as with 'Levo', a Dutch pickling cultivar. All data confirm the single recessive gene hypothesis (Table 1). We propose the designation "divided leaf", symbol dl (later renamed dvl to avoid conflict with a previously published gene), for this character. It has potential as a seedling marker and we have already used it as such in genetic studies.

Table 1. Results of crosses involving "divided leaf".

	Observed
Cross	Divided leaf	Normal	Expected ratio	Proposed genotypes	X2	p
318 (self) mutant	85	0	1:0	dl dl	-	-
319-2,3 (self) mutant	25	0	1:0	dl dl	-	-
318x319-1	3	0	1:0	dl dl x dl dl	-	-
318xLevo	0	155	0:1	dl dl x Dl Dl	-	-
319-4 (self) normal	17	47	1:3	Dl dl	0.083	0.773
319-5 (self) normal	79	243	1:3	Dl dl	0.037	0.847
319-4x319-2	95	93	1:1	Dl dl x dl dl	0.021	0.884
319-5x319-2	114	108	1:1	Dl dl x dl dl	0.162	0.687
F2 (318xLevo)	17	57	1:3	dl dl x Dl Dl	0.162	0.687