STRELIN Marina Micaela
The influences of progenitor filtering, domestication selection and the boundaries of nature on the domestication of grain crops
GARIBALDI LUCAS; AIZEN MARCELO; SAEZ AGUSTIN; GLEISER GABRIELA; STRELIN MARINA; HARDER LAWRENCE
WILEY-BLACKWELL PUBLISHING, INC
Lugar: Londres; Año: 2021
1. Domestication generally involves two sequential processes: initial identification of wildspecies with desirable characteristics (?progenitor filtering?); and subsequent artificial andnatural selection that respectively improve features preferred by humans and adapt species tocultivation/captivity (?domestication selection?). Consequently, domesticated species candiffer from wild species and may share characteristics owing to convergent evolution(?domestication syndrome?). Baring evolutionary constraints, domestication selection maygenerate extreme phenotypes that transcend the ?boundaries of nature? evident for wildspecies. Despite evidence of domestication syndromes in some clades, broader contributionsof progenitor filtering and domestication selection to characteristics of contemporarydomesticated species have received limited attention.2. Using comparative analysis of 49 grain-crop and 87 wild annual plant species from 15families, we: (1) addressed whether plants of crop and wild species differ for mean seednumber, per-seed mass and total seed-mass investment; (2) assessed contributions ofa) progenitor filtering and b) domestication selection to these differences; (3) evaluatedwhether crop characteristics exceed the boundaries of nature; and (4) assessed whether seedproduction characteristics of grain crops constitute components of a generic domesticationsyndrome.3. On average, grain-crop plants produce heavier seeds and greater total seed mass than wildspecies, but seed number per plant does not differ. Comparison of wild species betweengenera with or without crop species found no evidence of progenitor filtering. In contrast,crop species differed from congeneric wild species for the mass traits, but not for seednumber. Greater seed investment by crops is consistent with artificial selection for enhancedseed yield (mass per harvested area), whereas heavier individual seeds suggest selection forimproved nutritional quality and (or) adaptation to cultivation environments.4. Seed number-size characteristics of grain-crop species lie within the bivariate variation amongwild species and so do not exceed the boundaries of nature. Seed number and size variedsimilarly between species types and generally aligned with seed-investment isoclines,suggesting an upper investment limit.5. Despite greater average investment in seed production and individual seeds by grain-cropspecies, seed-production characteristics did not vary less among crop species than among wildspecies, which is inconsistent with a common domestication syndrome.