Relationships between reproductive output, morpho-physiological traits and life span in Lesquerella (Brassicaceae

GOZALEZ PALEO, L, RAVETTA, D.A.

Industrial Crops and Products

ELSEVIER SCIENCE BV

Año: 2011 vol. 34 p. 1386 - 1392

0926-6690

The development of perennial industrial crops could contribute to increase agriculture sustainabilityand yield stability in arid environments. Since perennial plants allocate resources preferentially to perpetuationand to structural and functional characters that provide drought tolerance, they tend to havelower reproductive output (yield) than their congeneric annuals. Four species of Lesquerella native toarid regions were evaluated to understand the relationships between reproduction, drought tolerance,and their association with the plant’s life span. We assessed the following set of characters (defined asplant strategies): phenology, gas exchange, specific leaf area, leaf area ratio, total biomass and biomassallocation. Annual (Lesquerella gracilis and Lesquerella angustifolia) and perennial (Lesquerella mendocinaand Lesquerella pinetorum) species were compared under water limiting conditions. Within this set ofspecies differences in structural and functional characters were observed. The annual, L. gracilis showed aplant strategy characterized by high reproductive output, harvest index (HI) and specific leaf area (SLA).L. mendocina (perennial), produced more total biomass, but had a low reproductive output, and alsoshowed characters that provide drought tolerance (high allocation to roots-root mass ratio (RMR), andstorage-total non structural carbohydrates (TNC) and low SLA). The annual L. angustifolia and the perennialL. pinetorum had intermediate plant strategies (i.e. intermediate values of traits typically related withannual or perennial life span). In the case of L. pinetorum we found some traits common to L. mendocina:long vegetative period, high biomass, CO2 assimilation rate (A), and water use efficiency (WUE), and lowSLA. The high reproductive output in L. pinetorum was a result of both, higher total biomass and longergrowing season compared to the annuals, and of higher HI in relation to the other perennial. These differencesin plant strategies among perennial Lesquerella show that there are different combinations oftraits that could be used as criteria for the selection of a perennial crop in programs of domestication forPatagonia and others arid lands