Inheritance of beta-carotene-associated flesh color in cucumber (Cucumis sativus L.) fruit

Abstract

The nutritional value of cucumber (Cucumis sativus L.) can be improved by the introgression of b-carotene (i.e., provitamin A and/or orange flesh) genes from ''Xishuangbanna gourd'' (XIS; Cucumis sativus var. xishuangbannanesis Qi et Yuan) into US pickling cucumber. However, the genetics of b-carotene content has not been clearly defined in this US market type. Thus, three previous populations derived from a US pickling cucumber ('Addis') 9 XIS mating were evaluated for b-carotene content, from which the high b-carotene inbred line (S 4 ), 'EOM 402-10', was developed. A cross was then made between the US pickling cucumber inbred line 'Gy7' [gynoecious, no b-carotene, white flesh; P 1 ] and 'EOM 402-10' [monoecious, possessing b-carotene, orange flesh; P 2 ] to determine the inheritance of b-carotene in fruit mesocarp and endocarp tissue. Parents and derived cross-progenies () were evaluated for b-carotene content in a greenhouse in Madison, Wisconsin. While F 1 and BC 1 P 1 progeny produced mature fruits possessing white, light-green, and green (0.01-0.02 lg g -1 b-carotene) mesocarp, the F 2 and BC 1 P 2 progeny mesocarp segregated in various hues of white, green, yellow (0.01-0.34 lg g -1 b-carotene), and orange (1.90-2.72 lg g -1 b-carotene). Mesocarp and endocarp F 2 segregation adequately fit a 15:1 [lowb-carotene (0.01-0.34 lg g -1 ): high-b-carotene (1.90-2.72 lg g -1 )] and 3:1 (low-b-carotene: highb-carotene) ratio, respectively. Likewise, segregation of carotene concentration in mesocarp and endocarp tissues in BC 1 P 2 progeny adequately fit a 3:1 (lowb-carotene: high-b-carotene) and 1:1 (low-b-carotene: high-b-carotene) ratio, respectively. Progeny segregations indicate that two recessive genes control the b-carotene content in the mesocarp, while one recessive gene controls b-carotene content in the endocarp. Single marker analysis of F 2 progeny using the carotenoid biosynthesis gene Phytoene synthase determined that there was no association between this gene and the observed b-carotene variation in either fruit mesocarp or endocarp.

Mapping of quantitative trait loci for lycopene content and fruit traits in Citrullus lanatus

“…Blast analysis results demonstrated that lycopene b-cyclase (Lcyb) mRNA, LCYB-red allele and complete cDNAs were detected in the same region between the two CAPS markers. In melon, seven genes from the carotenoid biosynthetic pathway have been previously mapped (Cuevas et al 2008(Cuevas et al , 2010, and five were re-mapped to similar locations with different markers, as reported by Harel-Beja and colleagues (Harel-Beja et al 2010). Identifying the gene and functional polymorphism underlying this position may further shed light on the carotenoid biosynthetic process.…”

“…QTL at chromosome 2 and 8 were associated with the presence and absence of flesh carotenoids, while the LSW-177 and COS F 2 population was established from a cross of red and pale yellow flesh color. Some studies showed that genetic manipulation of the quantity of b-carotene in cucumber and melon fruit (endocarp and mesocarp) was controlled by at least two recessive genes (Clayberg 1992;Cuevas et al 2010). It was suggested that the LG6 in melon QTL may contain a gene that stimulates the carotenoid metabolic pathway in general, leading to the formation of b-carotene (Monforte et al 2004;Cuevas et al 2008).…”

“…The inheritance of flesh color fit the pattern of two major genes plus polygene. Cuevas et al confirmed the recessive nature of the cucumber color gene (orange dominant to non-pigmentation) in the XIS-derived progeny, where two recessive genes controlled the orange coloration to b-carotene quantity (QbC) in the mesocarp, whereas one recessive gene controlled QbC in the endocarp (Cuevas et al 2010). Cayberg indicated that the green (gf) and white (wf) flesh in melon are recessive to orange, where the gf and wf interact epistatically (Clayberg 1992).…”

New genetic sources for orange color in cucumber (Cucumis sativus L.) fruit flesh

“…A number of genes that control exocarp color, which can also be orange, yellow, or cream-colored, have been described (Che and Zhang, 2019). Some cucumber varieties have colored flesh, such as yellow (Kooistra, 1971, Lu, H. W. et al , 2015) or orange (Simon and Navazio, 1997), due to carotenoid accumulation (Navazio and Simon, 2001, Cuevas et al , 2010), while the white flesh has no detectable ß-carotene and only trace amounts of total carotenoids (Kandlakunta et al , 2008). Carotenoids are yellow, orange, or red compounds with various functions in plants (Cazzonelli and Pogson, 2010).…”

Genetic Research on Fruit Color Traits of the Bitter Gourd (<i>Momordica charantia</i> L.)

“…The flesh color of watermelon was controlled by two genes (Shimotsuma, 1963), but Gusmini and Wehner (2006) mentioned the genetic model of flesh color in the watermelon was affected by one gene or multiple genes that depended on the combinations of parents with different flesh colors. Cuevas et al (2010a) found the inheritance of beta-carotene content in the cucumber mesocarp was controlled by two recessive genes which affected the phenotype of flesh color, but inheritance of beta-carotene content in the endocarp was dominated by one recessive gene. The color appearances of the mesocarp and endocarp were independent.…”