Effect of female and male genotypes and environment on wax composition in jojoba

Abstract

The objective of this study was to determine the effects of genotype and environment on wax composition in jojoba seed, and thus be able to control it. Production of waxes with different compositions-and hence changed wax properties such as viscosity, boiling point, and thermal stability-may be of importance for future requirements of the jojoba industry. Wax composition of 23 female clones was determined for two growing seasons. The ratio of FA elongated to the sum of those reduced and esterified differed among genotypes, resulting in differences in the percentage of wax esters longer than 40 or 42 carbons. The clones 'Yarden,' 'Gvati,' 'Hazerim,' 'BGU,' and 'Negev' had higher percentages of long-chain wax moieties than the clones '879-154,' 'MS 55-4,' and 'Forti.' The contribution of the male genotype to wax composition was tested by pollinating bagged female flowers of four female clones with pollen from three male plants. Both male and female genotypes additively influenced the composition of the wax esters. Wax composition varied between growing seasons and locations, but differences between genotypes were consistent. Salinity of the irrigation water did affect wax composition in some clones. Under high salinity, the salt-sensitive clone '64' produced a smaller percentage of long-chain wax esters, whereas in clone 'Q-106' wax composition did not change. In clone '874-154' the chain lengths of the wax moieties in the seeds increased under medium salinity. We conclude that jojoba wax composition is influenced by both female and male genotypes and by environmental factors such as climate and salinity.

A reliable gender diagnostic PCR assay for jojoba (Simmondsia chinensis (Link) Schneider)

“…In the present study a reliable jojoba male-specific marker was identified. In jojoba breeding studies the genetic properties of the male and female should be considered since the effect of the male and female parents on yield and wax compositions are additive and highly significant (Benzioni and Vaknin 2002).…”

“…The economic value of jojoba comes from its seeds which contain about 50-60% of a light yellow, odorless wax ester commonly referred to as jojoba oil. As many as 300 products containing jojoba have appeared in markets in recent years and the use of jojoba products will increase in future (Benzioni and Vaknin 2002;Benzioni et al 2005).…”

“…Differing from most of the cultivated crop species, jojoba has slow-growing habit, difficulties in the determination of sex at the early seedling stages, a male-biased (5:1; male: female) ratio and low seed yield (Benzioni and Vaknin 2002;Agrawal et al 2007;Sharma et al 2008). Commercial plantations of jojoba are mainly established using cuttings, or in a few cases grafting, resulting in a narrow genetic diversity that may cause the low seed yield (Dunstone et al 1985).…”

Renewable feedstocks for lubricant production

“…The approximate FA composition of JO oil, consisting for 98% of monounsaturated ω-9 FAs, is 66-71% C20:1 (cis-11-eicosenoic acid), 14-20% C22:1 and 10-13% C18:1 [284]. The fi nal composition of this unique storage-lipid wax is a result of activities and affi nities of three main enzymes: a fatty acyl-CoA elongase (β-ketoacyl-CoA synthase), which produces 20 : 1, 22 : 1 and 24 : 1 acyl CoA as precursors to the wax; fatty alcohol reductases (acyl CoA reductases); and acyl : alcohol transacylase [285].…”

Early determination of sex in jojoba plant by CAPS assay

“…However, a period of 3-6 years would be required for the new male plants to produce sufficient pollen to be effective. Furthermore, the selection of male plants for plantations requires genetic knowledge about them, since the effect of the male and female parents on yield and wax compositions are additive and highly significant (Benzioni & Vaknin 2002).…”