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In dry conditions, tall and fast‐growing wheat plants with good tolerance to drought may offer higher grain yields than ‘Green revolution’ wheat.

BackgroundVernalization genes VRN1 play a major role in the transition from vegetative to reproductive growth in wheat. In di-, tetra- and hexaploid wheats the presence of a dominant allele of at least one VRN1 gene homologue (Vrn-A1, Vrn-B1, Vrn-G1 or Vrn-D1) determines the spring growth habit. Allelic variation between the Vrn-1 and vrn-1 alleles relies on mutations in the promoter region or the first intron. The origin and variability of the dominant VRN1 alleles, determining the spring growth habit in tetraploid wheat species have been poorly studied.ResultsHere we analyzed the growth habit of 228 tetraploid wheat species accessions and 25 % of them were spring type. We analyzed the promoter and first intron regions of VRN1 genes in 57 spring accessions of tetraploid wheats. The spring growth habit of most studied spring accessions was determined by previously identified dominant alleles of VRN1 genes. Genetic experiments proof the dominant inheritance of Vrn-A1d allele which was widely distributed across the accessions of Triticum dicoccoides. Two novel alleles were discovered and designated as Vrn-A1b.7 and Vrn-B1dic. Vrn-A1b.7 had deletions of 20 bp located 137 bp upstream of the start codon and mutations within the VRN-box when compared to the recessive allele of vrn-A1. So far the Vrn-A1d allele was identified only in spring accessions of the T. dicoccoides and T. turgidum species. Vrn-B1dic was identified in T. dicoccoides IG46225 and had 11 % sequence dissimilarity in comparison to the promoter of vrn-B1. The presence of Vrn-A1b.7 and Vrn-B1dic alleles is a predicted cause of the spring growth habit of studied accessions of tetraploid species. Three spring accessions T. aethiopicum K-19059, T. turanicum K-31693 and T. turgidum cv. Blancal possess recessive alleles of both VRN-A1 and VRN-B1 genes. Further investigations are required to determine the source of spring growth habit of these accessions.ConclusionsNew allelic variants of the VRN-A1 and VRN-B1 genes were identified in spring accessions of tetraploid wheats. The origin and evolution of VRN-A1 alleles in di- and tetraploid wheat species was discussed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0924-z) contains supplementary material, which is available to authorized users.

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...

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Nosema bombi is an obligate intracellular parasite of bumblebees (Hymenoptera, Bombus spp.), which has significant negative effect on individual bumblebees, colony fitness, and development. Recently, several new genetic variants of N. bombi without a defined taxonomic status were identified in natural bumblebee populations from Russia, China, and several European countries, as well as N. ceranae, originally isolated from honey bees, was described in bumblebee species. Thus, it is required to investigate more Nosema variability in bumblebee populations for identifying new genetic Nosema variants. In our study, we used several methods such as total DNA isolation, polymerase chain reaction (PCR) amplification, cloning, sequencing, and comparative and phylogenetic analysis to investigate a prevalence of N. bombi and its diversity in the natural populations of bumblebees across West Siberia. DNA was extracted from intestinal bumblebee tissues. Identification of the parasite was conducted, using PCR with primers specific for the ribosomal RNA gene cluster and methionine aminopeptidase 2 gene of N. bombi followed by sequencing. Seven hundred twenty-seven individual bumblebees belonging to 16 species were tested; 64 specimens revealed presence of the parasite. Prevalence of Nosema bombi infection was different in each region and varied from 4 to 20 %. No infection was found in Bombus agrorum (n = 194) and Bombus equestris (n = 132), both common bumblebees in West Siberia. Three different genetic variants of the same species, N. bombi, were identified. The first variant belonged to N. bombi (AY008373) identified by Fies et al. (J Apicult Res 40:91-96, 2001), second (N. bombi WS2) was identical to the West Siberian variant identified by Szentgyörgyi et al. (Polish Journal of Ecology 59:599-610, 2011), and the last variant, N. bombi WS3, was new. The results led us to suggest that the prevalence of the N. bombi is related to the population structure of bumblebees and distribution of the particular genetic variants of N. bombi.

1 Федеральный исследовательский центр Институт цитологии и генетики Сибирского отделения Российской академии наук, Новосибирск, Россия 2 Новосибирский национальный исследовательский государственный университет, Новосибирск, Россия 3 Институт биологии, экологии и природных ресурсов, Кемеровский государственный университет, Кемерово, Россия 4 Институт наук об окружающей среде, Ягеллонский университет, Краков, Польша 5 Институт систематики и экологии животных Сибирского отделения Российской академии наук, Новосибирск, Россия В последние десятилетия наблюдается резкое снижение чис ленности популяций медоносных пчел и шмелей на террито рии большинства стран мира. Вклад в снижение численности данных опылителей вносят различные паразитические орга низмы (бактерии, грибы, простейшие, нематоды, клещи и на секомые). Паразиты рода Nosema (Microsporidia: Nosematidae) и родов Crithidia и Lotmaria (Kinetoplastida: Trypanosomatidae) оказывают значительное негативное влияние на численность медоносных пчел и шмелей. В недавних исследованиях, про веденных с использованием ядерных ДНКмаркеров, были описаны новые виды и генетические варианты данных парази тов. Целью настоящей работы являлось установление уровня зараженности медоносных пчел и шмелей микроспоридиями (Nosema spp.) и трипаносоматидами (Crithidia spp. и Lotmaria passim), а также изучение генетической вариабельности этих паразитов на ранее не исследованной территории Индии. В работе проанализировано 119 образцов из четырех видов медоносных пчел и пяти видов шмелей. Уровни зараженности популяций пчел и шмелей паразитическими организмами на территории двух штатов (Джамму и Кашмир, Карнатака) были определены с помощью полимеразной цепной реакции с праймерами, специфичными к кластеру генов рибосомной РНК Nosema, Crithidia и Lotmaria. Совместное заражение по пуляций медоносных пчел и шмелей микроспоридиями и трипаносоматидами было зафиксировано на территории штата Джамму и Кашмир. В результате сравнительного анализа нуклеотидных последовательностей кластера генов рибосом ной РНК установлено, что в популяциях медоносных пчел на территории Индии были представлены N. bombi, N. ceranae и L. passim. Популяции шмелей были поражены микроспориди ей Nosema D и трипаносоматидами Crithidia bombi и CrithidiaThe populations of honeybees and bumblebees have been decreasing around the world in the recent decades. A va riety of pathogens and parasites, including bacteria, fungi, protozoa, nematodes, mites and insects play signi ficant role in honeybee and bumblebee colonies loss. Pa rasites of the genus Nosema (Microsporidia: Nosematidae) and the genera Crithidia and Lotmaria (Kinetoplastida: Trypanoso matidae) have a significant negative impact on honeybee and bumblebee colonies. Recent studies of nuclear DNA markers of these parasites allowed to describe new species and genetic variants. The aim of this study was to investi gate the Microsporidia (Nosema spp.) and Trypanosoma tidae (Crithidia spp. and Lotmaria passim) prevalence and genetic diversity in honeybee and bumble bee populations ...

BackgroundIn rice, a variant of DEP1 gene results in erect panicle architecture, well-developed vascular bundles, an increase in the number of grains per panicle and a consequent increase in the grain yield. Interestingly, DEP1 homologs are present in the other cereals including species of wheat and barley (Hordeum vulgare), even though they do not produce panicles but spikes. In barley, HvDEP1 alleles do not differ between strains of various ear types and geographic origins, while in at least three OsDEP1 variants have been described.ResultsIn this work, we have studied the DEP1 gene from eight accessions which belong to four wheat species, T. monococcum, T. durum, T. compactum, and T. spelta, with either compact, compactoid or normal spike phenotypes. The nucleotide sequences of the 5th exon of DEP1 were determined for all eight accessions. Obtained sequences were species specific. Despite the interspecies diversity, all wheat sequences encoded polypeptides of the same size, similarly to the 5th exons of the DEP1 homologs in T. aestivum, T. urartu, and H. vulgare. For further study, the full-length sequences of the DEP1 gene for all four species were studied. The full-length DEP1 genomic copies were isolated from the genomic sequences of T. aestivum, T. urartu, and Aegilops tauschii.The genome of tetraploid wheat T. durum contains two variants of the DEP1 originating from A and B genomes. In the hexaploid wheats T. aestivum, T. compactum, and T. spelta, three variants of this gene originating from A, B, and D genomes were detected. DEP1 genes of the diploid wheats T. monococcum and T. urartu differ. It seems that a precursor of the DEP1 gene in T. monococcum originates from the wild progenitor T. boeoticum.ConclusionNo DEP1-related differences of nucleotide sequences between the compact (or compactoid) and normal spike phenotypes in the tested wheat species were detected. Therefore, DEP1 gene does not directly participate in the control of the spike architecture in wheats.Electronic supplementary materialThe online version of this article (10.1186/s12863-017-0583-6) contains supplementary material, which is available to authorized users.