Profiles of Carotenoids in Citrus Species, Their Relatives and Hybrids

摘要

Carotenoids are major components of the pigments of citrus fruit colors. We measured the contents of nine carotenoids (α-carotene, β-carotene, δcarotene, β-cryptoxanthin, lutein, phytoene, cis-violaxanthin, trans-violaxanthin, and zeaxanthin) in citrus flavedo and juice sacs. The flavedo possessed more carotenoids than the juice sacs. The diversities of the carotenoid components in the flavedo and juice sacs showed statistical differences from one generation to another. On the basis of these patterns, Citrus species and their relatives (CS, Citrus standard species, 75 specimens) , lst-to 3rdgeneration hybrids (lst-3rd GH, mainly intermediate parents, 70 specimens) , and 4th-to 6th-generation hybrids (4th-6th GH, progenies of the lst-3rd GH, 53 specimens) could be statistically divided according to the carotenoid components and their quantities. The quantities of α-carotene, β-cryptoxanthin, cisviolaxanthin, and total carotenoids (sum of the nine carotenoid components) varied considerably among the multiple-generation hybrids in the flavedo. In addition, the quantities of a-carotene and p-cryptoxanthin showed a statistical difference (P≤ 0. 01)in the flavedo. For the most part, the specimens of the Citrus standard species (CS) possessed 0. 5 to 20mg/100gFW of total carotenoids, whereas most of the multiple-generation hybrids contained more than l0mg/l00gFW in the flavedo. Compared with the CS, the total carotenoid contents were higher in the multiple-generation hybrids in the flavedo and juice sacs. The quantities of the carotenoid components, except for 8-carotene, trans-violaxanthin, and cis violaxanthin, varied considerably in the juice sacs among generations. In particular, a-carotene, βcarotene, and p-cryptoxanthin were increased in the flavedo and juice sacs by crossbreeding (P ≤ 0. 01). Therefore, pcryptoxanthin is an important component for differentiating among multiple-generation hybrids and increasing the total carotenoid content of citrus multiple-generation hybrids. Artificial citrus crossbreeding is useful for the nutritional improvement of the carotenoid profiles.