Crop Genotype and Plant Population Density Impact Flowering Phenology and Synchrony between Cropped and Volunteer Spring Wheat

Abstract

Wheat (Triticum aestivum L.) is one of many crops into which novel traits have been incorporated using recombinant DNA technology, and thus may require segregation from nontransgenic wheat. Volunteer wheat populations, which cannot be selectively removed from wheat crops, pose a challenge to segregation because they may serve to facilitate trait movement. However, diverse fl owering phenologies among wheat genotypes planted at various densities may result in fl owering asynchrony, thus minimizing pollen-mediated gene fl ow (PMGF). We tested this theory with a comparative analysis that examined the infl uence of crop plant population density, genotype, and height on fl owering phenology and synchrony between volunteer and cropped wheat populations. We found that time from crop sowing to fi rst fl ower, peak fl owering, and fl owering cessation varied signifi cantly among genotypes. Increasing crop plant population density resulted in accelerated crop fl owering for all genotypes, but had little eff ect on fl owering synchrony. Although not always signifi cant, the time interval from sowing to 5, 50, and 95% fl owering, as well as the fl owering duration of the volunteer population, were also greater at low crop plant population densities. Synchronicity of fl owering varied among genotypes, with tall genotypes consistently exhibiting more fl owering synchrony with volunteer wheat than short genotypes. However, the response of fl owering synchrony to height may have been a product of the genotypes tested and further study to confi rm these results is needed. Th e results of this study suggest that, despite a short fl owering period, there is considerable potential for fl owering synchrony between cropped and volunteer wheat populations. Nevertheless, opportunity exists to reduce fl owering synchrony between cropped and volunteer wheat populations by utilizing genotypic variation for fl owering phenology to minimize fl owering overlap, provided that an adequate crop plant population density is attained.

Different grain-filling rates explain grain-weight differences along the wheat ear

“…Here, only the ears originating from the main tillers were studied, also our plants were grown at a lower density than generally applies in the field. Nevertheless, Willenborg et al [26] observed a similar range of within-ear flowering times for four different wheat cultivars under field conditions. De Vries [27] studied flowering times on up to three ears per plant, in five spring-wheat varieties under greenhouse conditions.…”

Sowing date and sowing method influence on camelina cultivars grain yield, oil concentration, and biodiesel production

“…() was attributed to the greater plant density (12.5%) and TSW (7.4%) for Blaine Creek compared to Pronghorn. Crop phenology is an important regulatory mechanism that determines crop yield (Richards, ; Wu, Feng, Zhang, Gao, & Wang, ) and differs among cultivars within the same species (Rezaei, Siebert, Hüging, & Ewert, ; Willenborg, Luschei, Brûlé‐Babel, & Van Acker, ). In our study, with the exception of DASM in 2017, the phenological parameters were not different among the three cultivars of camelina and this similarity may support the lack of difference in grain yield possibly because of low genetic differentiation among the three cultivars.…”

Asynchronous flowering and within-plant flowering diversity in wheat and the implications for crop resilience to heat

“…Hence, florets of a single cereal genotype do not flower simultaneously. This variability in the temporal and spatial pattern of flowering has potential implications for (a) gene flow between plant populations (Demotes-Mainard et al, 1996;Willenborg et al, 2009); (b) plant breeding; and (c) physiological escape of those florets which are active before or after a major abiotic stress event (Saini and Aspinall, 1982;Zhao et al, 2010).…”