Spike Morphology Genes in Wheat Species (TriticumL.)

Abstract

Contributed by Nikolay P. GoncharovThe review examines the state of knowledge on genes that control the architectonics of wheat plant (spike morphology). It is shown that molecular genetic studies, which have been recently started, allow to find both the orthologous genes from relative species of wheat (barley, rye, etc.) and genes that were not previously used for breeding. Use of these genes for further breeding allows to produce modern wheat commercial cultivars. Key words: spike morphology, plant architecture, gene, wheat species, Triticum. per, we present current knowledge of the agronomically important spike morphology traits in wheat (subtribe Frumentaceae Dum., tribe Triticeae) and explore some of the recent findings in the area of identification of the genes underlying the spike morphology traits. SPIKE MORPHOLOGY TRAITS IN WHEAT SPECIESThe spike is one of the most important parts of a wheat plant. It includes the reproductive organs, produces the seeds, and ensures dispersal of the mature grains. Spike morphology greatly affects breeding, harvest procedures and the yield. Spikes of wheat species differ in several morphological characteristics, including threshability, the presence or absence of awns, spike shape, spike shattering, spike branching and supernumerary spikelets spike (Fig. 1).Threshability. Easy threshing ability is mainly dependent on the tenacity of the glumes covering the grains. The wild species possess hulled grains (syn. non free-threshing), which are covered by a tough glume that remains adhered to the grain after the threshing (Dorofeev and Korovina, 1979). Naked or free-threshing seeds of cultivated wheat species are rounded by soft glumes which release during threshing ( Fig. 1). Wheat varieties with free-threshing seeds appeared during domestication and significantly advanced the efficiency of the threshing process and led to wheat becoming a major crop all over the world (Zhang et al., 2011).The presence or absence of awns. Awns are the threadlike extensions of the lemma. They have photosynthetic function, increase the assimilation of water, and may promote high yield of wheat grown under water-limited conditions (Reynolds and Tuberosa, 2008;Maydup et al., 2010) (Fig. 1). Several comparative studies of the grain yield advantage in awned and awnless lines gave conflicting results. The comprehensive investigation of Rebetzke et al. (2016) showed that awned near-isogenic lines are characterised by slightly greater grain yield due to increased kernel size and reduced screening. It was also demonstrated that awnless wheats with acceptable yield and quality have provide advantage in more favourable environments and future changing climates.In diploid wheat species T. urartu Thum. ex Gandil., T. monococcum, and T. boeoticum Boiss., only awned spikes have been identified to date, but only T. sinskajae A. Filat. et Kurk. has awnless spikes (Dorofeev and Korovina, 1979). Among tetraploid wheat species, all except T. aethiopicum Jakubz. awnless forms were obtained by hybridisation wit...

Morphometry of the Wheat Spike by Analyzing 2D Images

“…Spikes differ in their shape, size, density, awnedness, color, and so on. The spike shape is controlled by a set of genes; their study will make it possible to purposefully create new cultivars with improved yield characteristics, easier threshing, and resistance to environmental factors [2]. The wheat inflorescence is a compound spike with a length of 5-17 cm and longer; it consists of a rachis and spikelets.…”

Morphometry of the Wheat Spike by Analyzing 2D Images

“…), accession KU 506 acquired using both the 'table' and 'clip' protocols. Each spike was classified according to the types of awnedness based on an expert estimate into awnless, awnletted, half-awned, and short-awned ( Figure 2A-D, respectively) [2]. Table 1 lists the distribution of spike images in this sample according to the types of protocol and awnedness pattern.…”

Genetics of Adaptation and Arkhitectonics of Wheat

“…Ген Q, как и ген VRN-1, является одним из основных генов, вовлеченных в процесс доместикации, и контролирует такие признаки, как ломкость-не ломкость колоса, голозерность-пленчатость, форма колоса (норма-спельтоидность), форма и жесткость чешуи, длина оси колосового стержня, высота растения и некоторые другие хозяйственно важные признаки пшениц [Simons et al, 2006;Konopatskaia et al, 2016].…”

“…обзор, Konopatskaia et al [2016]), адаптивность [Гончаров, 2012; Киселева, Салина, 2018; и др. ] и морфологию колоса [Amagai et al, 2017;Kosuge et al, 2008;Simons et al, 2006;и др.…”