Genetics and breeding of jojoba [Simmondsia chinensis (Link) Schneider]

Abstract

Jojoba, Simmondsia chinensis (Link) Schneider, is a dioecious, extremely heterogeneous perennial shrub, native to the Sonoran Desert of North America where it has long been known as a source of oil, used for medicine and food, as well as a browse plant. Analysis of jojoba oil revealed that it is a unique liquid wax, similar to sperm whale oil, maintaining viscosity at very high temperatures. Jojoba oil gained worldwide interest for industrial, pharmaceutical and cosmetic use, as a lubricant, and an ingredient for medicines, cosmetics, toiletries and livestock feed. Jojoba also gained interest for afforestation, abatement of desert creep, browse and development of marginal lands, as well as a source of income for local inhabitants. Seed propagation is not economical and rooted cuttings from selected elites are the current commercial means of propagation. Cultivars with high yield and oil quality were selected and given mainly coded names. The females Barindji, Wadi-Wadi and Waradgery, and males Dadi and Guyambul were selected in Australia. Equipment has been developed in Argentina for transplanting cuttings, pruning the plants and preparing the soil surface for harvest. Environmental variation has significant effect on jojoba yield. The feasibility is demonstrated of using RAPD-PCR in distinguishing between jojoba sexes and producing wax esters in transgenic plants by expression of genes derived from jojoba. Rutherglen bug, aphids and Heliothis caterpillar insects, spider mites, Fusarium oxysporum and black scab (Elsinoe sp.) fungi cause minor damage to jojoba.