Dryland Wheat Domestication Changed the Development of Aboveground Architecture for a Well-Structured Canopy

Abstract

We examined three different-ploidy wheat species to elucidate the development of aboveground architecture and its domesticated mechanism under environment-controlled field conditions. Architecture parameters including leaf, stem, spike and canopy morphology were measured together with biomass allocation, leaf net photosynthetic rate and instantaneous water use efficiency (WUEi). Canopy biomass density was decreased from diploid to tetraploid wheat, but increased to maximum in hexaploid wheat. Population yield in hexaploid wheat was higher than in diploid wheat, but the population fitness and individual competition ability was higher in diploid wheats. Plant architecture was modified from a compact type in diploid wheats to an incompact type in tetraploid wheats, and then to a more compact type of hexaploid wheats. Biomass accumulation, population yield, harvest index and the seed to leaf ratio increased from diploid to tetraploid and hexaploid, associated with heavier specific internode weight and greater canopy biomass density in hexaploid and tetraploid than in diploid wheat. Leaf photosynthetic rate and WUEi were decreased from diploid to tetraploid and increased from tetraploid to hexaploid due to more compact leaf type in hexaploid and diploid than in tetraploid. Grain yield formation and WUEi were closely associated with spatial stance of leaves and stems. We conclude that the ideotype of dryland wheats could be based on spatial reconstruction of leaf type and further exertion of leaf photosynthetic rate.

Partial and full root-zone drought stresses account for differentiate root-sourced signal and yield formation in primitive wheat

“…Domesticated wheats are widely found at all three ploidy levels, whereas primitive wheats only exist at diploid and tetraploid levels [30]. From the perspective of evolution theory, primitive wheat may preserve a series of adaptive strategies under water limiting condition and maintain the reproductive capability [31, 32]. As is well known, primitive wheat species are the genetic donors of modern wheat germplasm resource, with critical unknown merit strategies to adapt to dry environment in their genome.…”

Optimizing single irrigation scheme to improve water use efficiency by manipulating winter wheat sink-source relationships in Northern China Plain

“…Improving sink and source capacity simultaneously, and coordinating the “sink-source” relationships is a highly promising approach to increase biomass and yield [ 8 , 13 , 16 ]. Irrigation event can affect source and sink capacity and further influence grain yield [ 16 , 18 , 37 ]. Theoretically, increasing leaf area and maintaining leaf activity after anthesis is more important for dry matter production and grain yield [ 38 ].…”

“…Many factors affect the “sink-source” relationships, including genotype, air temperature, rainfall and irrigation at different growth phases. However, irrigation is one of the most important factors affecting grain yield and WUE by manipulating “sink-source” relationships directly or indirectly [ 16 , 18 – 20 ]. In areas where groundwater is seriously over-exploited in NCP, water shortages are becoming more serious [ 21 ], and irrigation is allowed only once during the wheat growth period.…”

Effect of Drought on Morphological and Physiological Characteristics of Hybrids and Parental Forms of Wheat

“…reducing the degree of injury in drought conditions 4,5 . Studies by Chinese scientists have shown that the selection of plants by morphological features, by architectonics, and their crossing has the potential to increase grain yield under drought conditions [6][7][8] . With a favorable combination of components, high values of indicators are observed in F1 compared with parental forms.…”