TITLE:
Differences in Morphological, Physiological and Growth Traits between Two Endemic Subspecies of Brassica rupestris Raf.: Implications for Their Conservation
AUTHORS:
Maria Fiore Crescente, Loretta Gratani
KEYWORDS:
Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola; Brassica rupestris Raf. subsp. rupestris; Conservation; Drought Stress; Endemism; Global Change; Growth Analysis; Physiological Traits; Red-Listed Species
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.6A,
June
19,
2013
ABSTRACT:
The goal of this work was to analyze the
phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf.
subsp. rupestris to environmental factors also in consideration of global change. We used seedlings of the two
subspecies originated from wild plants from the natural habitats in Sicily and
cultivated in the Botanical Garden of Rome. Leaf morphological and
physiological traits and growth dynamic were analyzed as well as the
response to an imposed water stress experiment. The results underlined a higher relative growth rate in plant height (RGRH, cm·cm-1·d-1) in B. rupestris subsp. rupestris also attested by the highest plant
height (H, cm), leaf area (LA, cm2), specific leaf area (SLA, cm·g-1), total leaf area per plant (TLA, cm2)
and total plant dry mass (PDM, g plant-1). Moreover,
the significantly highest net photosynthetic rates (A, μmol CO2 m-2·s-1) during the study period of
this subspecies was related to the high Chlorophyll content (Chl, SPAD
units). B. rupestris subsp. rupestris was also the most tolerant subspecies to imposed water stress showing
the highest relative water content (RWC,
%), A and water use efficiency (WUE, μmol·mmol-1).