Potential value of traits associated with perennial habit in the development of new oil-seed crops for arid lands. A comparison of Lesquerella fendleri andL. mendocina subjected to water stress

PLOSCHUK, E., ; WINDAUER, L, ; RAVETTA, D.A.

JOURNAL OF ARID ENVIRONMENTS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2001 vol. 47 p. 373 - 386

0140-1963

Lesquerella fendleri is an annual new oil-seed crop under the process of domestication.Lesquerella mendocina, on the other hand, is a perennial species native tothe Monte region in Argentina and is not in the process of domestication at thepresent time. We analysed the impact of the perennial habit on several characteristicsthat might contribute to confer higher performances in sites withsevere water stress limitations. Two experiments were carried out under controlledtemperatures during two consecutive seasons. Biomass investment inroots and other vegetative organs, flowering rates between plants and within theplant, and gas exchange parameters were measured in L. fendleri andL. mendocina in both well-watered and water-stressed plants during flowering.Water stress increased the duration of the flowering phase by up to 15 days inL. fendleri and reduced the rate of stem production per plant by 20% at 110days after sowing (DAS) in both species (p(0·01). Independently of thewater treatment, only a fraction of the plants reached the reproductive stage inL. mendocina, while the number of reproductive stems per flowered plant was50% lower than in L. fendleri (p(0·05). L. mendocina partitioned a higherproportion of biomass to roots and above-ground vegetative organs(p(0·05), and leaf water-use efficiency (WUE) was 35% higher (p(0·05). The comparison of two related species of the same genus differingin life cycle clearly suggests that some traits of perennials have the potential tobe introduced in breeding programmes for new oil-seed crops for arid lands.( 2001 Academic PressKeywords: Lesquerella; perennials; reproductive costs; water stress; drought;biomass allocation; WUE