Biology subjects

Vercellino, R. B.

Publications and source records attributed to Vercellino, R. B..

3 recordsLinked to original sources

bioRxiv2020

Interference of feral radish (Raphanus sativus) resistant to AHAS-inhibiting herbicides in oilseed rape, wheat and sunflower crops

Raphanus sativus (feral radish), a cosmopolitan weed, has developed resistance to acetohydroxyacid synthase (AHAS) inhibitor herbicides in several countries of South America. This study reports the effects of season-long interference of several feral radish densities on grain yield and yield components of oilseed rape, wheat and sunflower, and on feral radish traits under field conditions. Feral radish density treatments consisted of 0, 2, 4, 8 and 16 plants m-2 in oilseed rape, 0, 4 and 12 plants m-2 in wheat, and 0, 1.6, 4, 8 and 16 plants m-2 in sunflower. The number of inflorescences per area, seeds per inflorescence and the seed biomass of crops were reduced with increasing feral radish densities. The rectangular hyperbola model revealed yield losses by up to 100 %, 74.4 % and 12.2 % in oilseed rape, wheat and sunflower, respectively. Feral radish seed production ranged from 4,300 to 31,200, and 1000 to 4,700 seeds m-2 in winter crops and sunflower, respectively. Season-long feral radish interference can result in serious economic losses in oilseed rape, wheat and sunflower. The adverse impact of feral radish on the yield of winter and summer crops and the high feral radish seed and pods production suggests the need for the development and implementation of diverse and effective long-term weed management practices.

plant biology↗

bioRxiv2020

Ecological fitness cost associated with the AHAS Trp574Leu mutation in feral Raphanus sativus

Gene mutations endowing herbicide resistance may have negative pleiotropic effects on plant fitness. Quantifying these effects is critical for predicting the evolution of herbicide resistance and developing management strategies for herbicide-resistant weeds. This study reports the effects of the acetohydroxyacid synthase (AHAS) Trp574Leu mutation throughout the life cycle of the weed feral radish (Raphanus sativus L.). Resistant and susceptible biotypes responded differently to light and water treatments in relation to germination and emergence. Under light exposure, the resistant biotype showed higher germination and emergence, but no differences were found in seed dormancy, germination in darkness and emergence from buried seeds or pods. The resistant biotype showed delayed and reduced seedling emergence relative to the susceptible biotype under rainfed conditions, but these differences between the biotypes were not detected in irrigated soil. The biotypes showed similar relative growth rates and vegetative biomass. However, under wheat interference, resistant plants had 36-46% less total above-ground biomass, 26-47% less seeds per plant, and 36-53% less plant yield than susceptible ones, and these differences were more evident at higher plant density. This study provides a better understanding of the ecological fitness cost associated with the AHAS Trp574Leu mutation in feral R. sativus. The fitness costs could reduce the frequency of the resistant allele in areas untreated with AHAS inhibiting herbicides.

evolutionary biology↗

bioRxiv2020

Maternal control of early life history traits affects overwinter survival and seedling phenotypes in sunflower (Helianthus annuus L.)

When cultivated and wild plants hybridize, hybrids often show intermediate phenotypic traits relative to their parents, which make them unfit in natural environments. However, maternal genetic effects may affect the outcome of hybridization by controlling the expression of the earliest life history traits. Here, using wild, cultivated, and reciprocal crop-wild sunflower (Helianthus annuus L.) hybrids, we evaluated the maternal effects on emergence timing and seedling establishment in the field, and on seedling traits under controlled conditions. In the field, we evaluated reciprocal crop-wild hybrids between two wild populations with contrasting dormancy (the high dormant BAR and the low dormant DIA) and one cultivar (CROP) with low dormancy. Under controlled conditions, we evaluated reciprocal crop-wild hybrids between two wild populations (BAR and RCU) and one CROP under three contrasting temperature treatments. In the field, BAR overwintered as dormant seeds whereas DIA and CROP showed high autumn emergence ([~]50% of planted seeds), resulting in differential overwinter survival and seedling establishment in the spring. Reciprocal crop-wild hybrids resembled their female parents in emergence timing and success of seedling establishment. Under controlled conditions, we observed large maternal effects on most seedling traits across temperatures. Cotyledon size explained most of the variation in seedling traits, suggesting that the maternal effects on seed size have cascading effects on seedling traits. Maternal effects on early life history traits affect early plant survival and phenotypic variation of crop-wild hybrids, thus, they should be addressed in hybridization studies, especially those involving highly divergent parents like cultivated species and their wild ancestors.

plant biology↗