Tikhenko N, Rutten T, Tsvetkova N, Voylokov A, Börner A
SPb Branch Vavilov Institute of General Genetics, St. Petersburg, Russia; Department of Genetics and Breeding, St. Petersburg State University, St. Petersburg, Russia; Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany.
Plant Biol (Stuttg). 2015 Mar;17(2):320-6. doi: 10.1111/plb.12237. Epub 2014 Sep 22.
The existence of hybrid dwarfs from intraspecific crosses in wheat (Triticum aestivum) was described 100 years ago, and the genetics underlying hybrid dwarfness are well understood. In this study, we report a dwarf phenotype in interspecific hybrids between wheat and rye (Secale cereale). We identified two rye lines that produce hybrid dwarfs with wheat and have none of the hitherto known hybrid dwarfing genes. Genetic analyses revealed that both rye lines carry a single allelic gene responsible for the dwarf phenotype. This gene was designated Hdw-R1 (Hybrid dwarf-R1). Application of gibberellic acid (GA3 ) to both intraspecific (wheat-wheat) and interspecific (wheat-rye) hybrids showed that hybrid dwarfness cannot be overcome by treatment with this phytohormone. Histological analysis of shoot apices showed that wheat-rye hybrids with the dwarf phenotype at 21 and 45 days after germination failed to develop further. Shoot apices of dwarf plants did not elongate, did not form new primordia and had a dome-shaped appearance in the seed. The possible relationship between hybrid dwarfness and the genes responsible for the transition from vegetative to generative growth stage is discussed.
100年前就已描述了小麦（普通小麦）种内杂交产生的杂种矮化现象，并且杂种矮化的遗传学原理也已被充分了解。在本研究中，我们报道了小麦与黑麦（黑麦草）种间杂种中的一种矮化表型。我们鉴定出两个黑麦品系，它们与小麦杂交会产生杂种矮化植株，且不携带任何迄今已知的杂种矮化基因。遗传分析表明，这两个黑麦品系都携带一个导致矮化表型的单等位基因。该基因被命名为Hdw-R1（杂种矮化-R1）。对种内（小麦-小麦）和种间（小麦-黑麦）杂种施用赤霉素（GA3）表明，这种植物激素处理无法克服杂种矮化现象。对发芽后21天和45天具有矮化表型的小麦-黑麦杂种的茎尖进行组织学分析表明，它们无法进一步发育。矮化植株的茎尖没有伸长，没有形成新的原基，并且在种子中呈圆顶状外观。本文还讨论了杂种矮化与负责从营养生长阶段向生殖生长阶段转变的基因之间的可能关系。
