scholarly journals Morphological and Genetic Mechanisms Underlying Awn Development in Monocotyledonous Grasses

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 573 ◽  
Author(s):  
Ntakirutimana ◽  
Xie

The identification of biological mechanisms underlying the development of complex quantitative traits, including those that contribute to plant architecture, yield and quality potential, and seed dispersal, is a major focus in the evolutionary biology and plant breeding. The awn, a bristle-like extension from the lemma in the floret, is one of the distinct morphological and physiological traits in grass species. Awns are taught as an evolutionary trait assisting seed dispersal and germination and increasing photosynthesis. Awn development seems to be complex process, involving dramatic phenotypic and molecular changes. Although recent advances investigated the underlying morphological and molecular genetic factors of awn development, there is little agreement about how these factors interact during awn formation and how this interaction affects variation of awn morphology. Consequently, the developmental sequence of the awn is not yet well understood. Here, we review awn morphological and histological features, awn development pathways, and molecular processes of awn development. We argue that morphological and molecular genetic mechanisms of awn development previously studied in major cereal crops, such as barley, wheat, and rice, offered intriguing insights helping to characterize this process in a comparative approach. Applying such an approach will aid to deeply understand factors involved in awn development in grass species.

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 2144 ◽  
Author(s):  
De Niu ◽  
Yuehui He

Seed development is a complex process and consists of two phases: embryo morphogenesis and seed maturation. LEAFY COTYLEDON (LEC) transcription factors, first discovered in Arabidopsis thaliana several decades ago, are master regulators of seed development. Here, we first summarize molecular genetic mechanisms underlying the control of embryogenesis and seed maturation by LECs and then provide a brief review of recent findings in the role of LECs in embryonic resetting of the parental ‘memory of winter cold’ in Arabidopsis. In addition, we discuss various chromatin-based mechanisms underlying developmental silencing of LEC genes throughout the post-embryonic development to terminate the embryonic developmental program.


2020 ◽  
pp. 160-168
Author(s):  
I. Senyk

Botanical composition of grasses is one of the most important indicators the biological value and quality of the obtained hay and pasture forage, the longevity of hayfi elds and pastures depend on. The issue of changing the botanical composition of agrophytocenoses is especially important in the context of global climate change, which in recent decades is also manifested in the territory of Ukraine, as it is possible to establish the most adapted species of legumes and cereals to adverse weather conditions and to identify eff ective technological methods of managing these processes for maximum conservation economically valuable species in the herbage. The purpose of the research is to establish the infl uence of diff erent ways of sowing of clover and alfalfa cereal crops agrophytocenoses on the formation of their botanical composition. Field studies have established diff erent eff ects of conventional in-line, cross-section and cross-sectional methods of sowing on the formation of botanical composition of grass mixtures of clover meadow (Trifolium pratense) varieties Sparta and Pavlyna with timothy meadow (Phleum pratense) and fenugreek multifl oral (Lolium multifl orum) and of agrophytocenoses of alfalfa of Sinyukha and Seraphima sowing varieties with reed fire (Festuca arundinacea Schreb) and middle wheatgrass (Elytrigia intermedia). For the average of four years of life of clover and alfalfa cereal crops agrophytocenoses, the highest proportion of legume component was observed with split-cross sowing – 51.6 % for Sparta, 53.1 % for Pavlyna, 60.3 % for Seraphima and 61.6 % for the Sinyukha variety. In the fourth year of life (the third year of use) of sowed leguminous-cereals agrophytocenoses, the preservation of the legume component was 14.6–15.5 % in clover-cereals grass mixtures with the Sparta variety and 16.0–16.8 % with the Pavlyna variety. In alfalfa grasslands, these indicators were 54.0–55.1 % with Seraphim and 55.0–56.2 % with Sinyukha. Among the studied varieties of clover meadow and alfalfa sowing proved better in the conditions of the Forest Steppe of western Pavlyna and Sinyukha. Cross-sectional and divided cross-sectional sowing of legumes and cereals mixtures proved to be better compared to conventional row crops in terms of conservation of economically valuable grass species. Key words: agrophytocenosis, botanical composition, clover meadow, alfalfa sowing, sowing methods.


2016 ◽  
Vol 106 (4) ◽  
pp. 362-371 ◽  
Author(s):  
P. Cheng ◽  
X. M. Chen ◽  
D. R. See

Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.


2015 ◽  
Vol 66 (4) ◽  
pp. 308 ◽  
Author(s):  
Alison. J. Frischke ◽  
James R. Hunt ◽  
Dannielle K. McMillan ◽  
Claire J. Browne

In the Mallee region of north-western Victoria, Australia, there is very little grazing of crops that are intended for grain production. The success of dual-purpose crops in other regions in south-eastern Australia with higher and more evenly distributed rainfall has driven interest in assessing the performance of dual-purpose cereals in the region. Five experiments were established in five consecutive years (2009–13) in the southern Mallee to measure the forage production and grain yield and quality response in wheat and barley to grazing by sheep or mechanical defoliation. The first three experiments focused on spring cultivars sown from late April to June, and the last two on winter cultivars planted from late February to early March. Cereal crops provided early and nutritious feed for livestock, with earlier sowing increasing the amount of dry matter available for winter grazing, and barley consistently produced more dry matter at the time of grazing or defoliation than wheat. However, the grain-production response of cereals to grazing or defoliation was variable and unpredictable. Effects on yield varied from –0.7 to +0.6 t/ha, with most site × year × cultivar combinations neutral (23) or negative (14), and few positive (2). Changes in grain protein were generally consistent with yield dilution effects. Defoliation increased the percentage of screenings (grains passing a 2-mm sieve) in three of five experiments. Given the risk of reduced grain yield and quality found in this study, and the importance of grain income in determining farm profitability in the region, it is unlikely that dual-purpose use of current cereal cultivars will become widespread under existing grazing management guidelines for dual-purpose crops (i.e. that cereal crops can be safely grazed once anchored, until Zadoks growth stage Z30, without grain yield penalty). It was demonstrated that early-sown winter wheat cultivars could produce more dry matter for grazing (0.4–0.5 t/ha) than later sown spring wheat and barley cultivars popular in the region (0.03–0.21 t/ha), and development of regionally adapted winter cultivars may facilitate adoption of dual-purpose cereals on mixed farms.


2021 ◽  
Author(s):  
Julia I Wucherpfennig ◽  
Timothy R Howes ◽  
Jessica N Au ◽  
Eric H Au ◽  
Garrett A Roberts Kingman ◽  
...  

Understanding the genetic mechanisms leading to new traits is a fundamental goal of evolutionary biology. We show that HOXDB regulatory changes have been used repeatedly in different stickleback fish species to alter the length and number of bony dorsal spines. In Gasterosteus aculeatus, a variant HOXDB allele is genetically linked to shortening an existing spine and adding a spine. In Apeltes quadracus, a variant allele is associated with lengthening an existing spine and adding a spine. The alleles alter the same conserved non-coding HOXDB enhancer by diverse molecular mechanisms, including SNPs, deletions, and transposable element insertions. The independent cis-acting regulatory changes are linked to anterior expansion or contraction of HOXDB expression. Our findings support the long-standing hypothesis that natural Hox gene variation underlies key morphological patterning changes in wild populations and illustrate how different mutational mechanisms affecting the same region may produce opposite gene expression changes with similar phenotypic outcomes.


2021 ◽  
Vol 901 (1) ◽  
pp. 012038
Author(s):  
Yu M Mavlyutov ◽  
A O Shamustakimova ◽  
I A Klimenko

Abstract Using the SCoT marker system, 8 varieties of cereal grasses belonging to 5 species were analyzed: Festuca pratensis, Lolium perenne, Lolium multiflorum, Festuca rubra, Festulolium. Of the 10 tested SCoT markers, 7 informative markers were selected that reveal interspecies genetic polymorphism. According to the results of the analysis, DNA profiles characteristic of each studied species were obtained, and primers allowing to detect intervarietal differences for subsequent identification and molecular genetic passportization were selected.


2019 ◽  
Author(s):  
Shan Gao

AbstractHeterosis has been widely exploited in animal and plant breeding to enhance the productive traits of hybrid progeny of two breeds or two species. Although, there were multiple models for explaining the hybrid vigor, such as dominance and over-dominance hypothesis, its underlying molecular genetic mechanisms remain equivocal. The aim of this study is through comparing the different expression genes (DEGs) and different alternative splicing (DAS) genes to explore the mechanism of heterosis. Here, we performed a genome-wide gene expression and alternative splicing analysis of two heterotic crosses between donkey and horse in three tissues. The results showed that the DAS genes influenced the heterosis-related phenotypes in a unique than DEGs and about 10% DEGs are DAS genes. In addition, over 69.7% DEGs and 87.2% DAS genes showed over-dominance or dominance, respectively. Furthermore, the “Muscle Contraction” and “Neuronal System” pathways were significantly enriched both for the DEGs and DAS genes in muscle. TNNC2 and RYR1 genes may contribute to mule’s great endurance while GRIA2 and GRIN1 genes may be related with mule’s cognition. Together, these DEGs and DAS genes provide the candidates for future studies of the genetic and molecular mechanism of heterosis in mule.


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