Authors:B. Feng, Z.B. Xu, X. Wang, F. Jiang, G.J. Zhao, C. Xiang, and T. Wang
High molecular weight (HMW) glutenin subunits are important seed storage proteins in wheat and its related species. Novel HMWglutenin subunits in Aegilops tauschii accession of TA2484 were detected and characterized. SDS-PAGE analysis revealed the y-type subunit from TA2484 displayed similar electrophoretic mobility compared to that of 1Dy12 subunit. However, the electrophoretic mobility of x-type subunit was faster than that of 1Dx2 subunit. The primary structure of the two cloned subunits from TA2484 was similar to that of the x- and y-type subunits reported before. However, the 148 residues of the x-type subunit, which contained the sequence element GHCPTSLQQ, in the middle of the repetitive domain was quite different from other x-type subunits. Moreover, the 68 residues in this region were identical to those of the y-type subunits from the same accession. Consequently, 1Dx2.3*t (x-type subunit of TA2484) contains an extra cystenin residue located at the repetitive domain, which is novel compared to the x-type subunits reported so far. Phylogenetic analysis indicated that two subunits from accession TA2484 were in the x- and y-type subunit cluster, but bootstrapping value of 100% gave high support for the spilt between two subunits (1Dx2.3*t and 1Dy12.3*t) and their alleles, respectively. A hypothesis on the genetic mechanism generating this novel sequence of 1Dx2.3*t subunit is suggested.
Authors:X.M. Fang, H.Z. She, C. Wang, X.B. Liu, Y.S. Li, J. Nie, R.W. Ruan, T. Wang, and Z.L. Yi
Waxy wheat (Triticum aestivum L.) is grown throughout the world for its specific quality. Fertilization and planting density are two crucial factors that affect waxy wheat yield and photosynthetic capacity. The objectives of the research were to determine the effects of fertilization and planting density on photosynthetic characteristics, yield, and yield components of waxy wheat, including Yield, SSR, TGW, GNPP, GWPP, PH, HI, Pn, Gs, Ci, E and WUE using the method of field experiment, in which there were three levels (150, 300, and 450 kg ha−1) of fertilizer application rate and three levels (1.35, 1.8, and 2.25 × 106 plants ha−1) of planting density. The results suggested that photosynthetic characteristics, yield, and yield components had close relationship with fertilization levels and planting density. Under the same plant density, with the increase of fertilization, Yield, SSR, TGW, GNPP, GWPP, HI, Pn, Gs, E and WUE increased and then decreased, PH increased, but Ci decreased. Under the same fertilization, with the increase of plant density, Yield, SSR, TGW, GNPP, GWPP, HI increased and then decreased, PH, Pn, Gs and E increased, PH and WUE declined. The results also showed that F2 (300 kg ha−1) and D2 (1.8 × 106 plants ha−1) was a better match in this experiment, which could obtain a higher grain yield 4961.61 kg ha−1. Consequently, this combination of fertilizer application rate and plant densities are useful to get high yield of waxy wheat.
Authors:J.C. Zheng, T. Liu, J.Q. Li, X. Wang, W.Y. Li, F. Xu, and Q.W. Zhan
Barley stripe mosaic virus (BSMV)-based virus induced gene silencing (VIGS) is an effective strategy for rapid determination of functional genes in wheat plants. ERECTA genes are reported to regulate stomatal pattern of plants, and manipulation of TaERECTA (a homologue of ERECTA in bread wheat) is a potential route for investigating stomatal development. Here, the leucine-rich repeat domains (LRRs) and transmembrane domains of TaERECTA were selected to gain BSMV:ER-LR and BSMV:ER-TM constructs, respectively, targeting TaERECTA for silencing in wheat cultivars ‘Bobwhite’ and ‘Cadenza’, to identify the function of TaERECTA on stomatal patterns. The results showed that reduced expression of TaERECTA caused an increased stomatal and epidermal cell density by average 13.5% and 3.3%, respectively, due to the significantly reduced size of leaf epidermal and stomatal cells, and this led to an increase in stomatal conductance. These suggest that modulation of TaERECTA offers further opportunities in stomatal engineering for the adaptation of photosynthesis in wheat.
Authors:J.Q. Xu, L. Wang, B.L. Liu, T.F. Xia, D.C. Liu, X. Chang, T.W. Zhang, H.G. Zhang, and Y.H. Shen
As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies.
Authors:K.J. Deng, J.P. Zhou, X.H. Wu, G. Sun, T. Wang, A.T. Tang, X.L. Zheng, and Y. Zhang
It is well demonstrated that wheat-rye 1BL/1RS translocated chromosome leads to some valuable novel traits such as disease resistance, high yield and functional stay-green after anthesis. To understand the physiological mechanism of 1BL/1RS translocation responsible for osmotic stress, two wheat cultivars, CN12 and CN17, carrying the translocated chromosome and MY11 without the translocated chromosome were employed in the study. During 5-day osmotic stress, fresh weight inhibition, chlorophyll content, soluble protein content, MDA concentration, antioxidant enzymes activity and free polyamines content were examined. CN12 and CN17, especially cultivar CN17, registered greater biomass and minor oxidative damage compared with their wheat parent. Meanwhile, the concentration of Spd and Spm in CN17 was significantly higher than the others. In addition, we found a positive correlation of fresh weight inhibition (FWI) and Put concentration, and a negative one with the parameters (Spd + Spm): Put ratio, indicating the importance of higher polyamine (Spd and Spm) accumulation on the adaptation to osmotic stress. Therefore, we proposed that the accumulation of higher polyamines (Spd and Spm) should play an important role on the adaptation of 1BL/1RS translocation lines to osmotic stress and might be important factors for the origin of novel traits introduced by 1BL/1RS.
Authors:W.T. Xue, A. Gianinetti, R. Wang, Z.J. Zhan, J. Yan, Y. Jiang, T. Fahima, G. Zhao, and J.P. Cheng
Crop seeds are the main staples in human diet, especially in undeveloped countries. In any case, the diet needs to be rich not only in macro-nutrients like carbohydrates and protein, but also in micro-nutrients. Nevertheless, both the macro- and micro-nutrients presented in seeds largely vary in consequence of field and environment conditions. In this research, 60 lines of a barley RILs population segregating for the SSR marker Hvm74, which is genetically linked to the GPC (grain protein content) locus (HvNAM-1), were studied in 4 environments (two growing years and two field managements) by carrying out a comprehensive profile of seed macro- (starch, total nitrogen and total soluble protein) and micro-nutrients (phytate, phenolics, flavonoids, Pi, Zn and Fe). Under field conditions, all the components were largely affected by the environment, but TN (total nitrogen) exhibited high genotype contribution, while micro-nutrients displayed higher genotype × environments interactions (GEI) than macro-nutrients. In order to approach the effects of carbon-nitrogen (C–N) balance on other seed components, two C/N ratios were calculated: C/TN (CNR1) and C/TSP (CNR2). CNR2 exhibited stronger negative correlations with all micro-nutrients. Hence, the significant GEI and its negative relationships with CNR2 highlighted the different characters of micro-nutrients in barley seeds.
Authors:S. Wang, D. Chen, G. Guo, T. Zhang, S. Jiang, X. Shen, D. Perovic, S. Prodanovic, and Y. Yan
In this work, 9 novel LMW-GS genes (6 LMW-m and 3 LMW-i type) from 4 diploid and 1 tetraploid Aegilops species were amplified and cloned by allelic-specific PCR. Analysis of the deduced amino acid sequences showed that 7 and 2 LMW-GS had 9 and 7 cysteines, respectively. Four LMW-m type subunits genes had an extra cysteine at the C-terminal III, which could form intermolecular disulphide bonds to extend the chains, and therefore would facilitate to form larger gluten polymers. This suggested that these genes are expected to be used as candidate genes for wheat quality improvement. The correlation between specific N-terminal sequences and a decapeptide deletion in the C-terminal II in LMW-GS encoded by D genome was found. Particularly, if LMW-GS possessed a METRCIPG-N-terminal beginning sequences and a decapeptide (LGQCSFQQPQ) deletion in the C-terminal II, they could be encoded by D genome.
Authors:B.L. Béres, N.Z. Lupwayi, F.J. Larney, B. Ellert, E.G. Smith, T.K. Turkington, D. Pageau, K. Semagn, and Z. Wang
Research indicates that not all crops respond similarly to cropping diversity and the response of triticale (× Triticosecale ssp.) has not been documented. We investigated the effects of rotational diversity on cereals in cropping sequences with canola (Brassica napus L.), field pea (Pisum sativum L.), or an intercrop (triticale:field pea). Six crop rotations were established consisting of two, 2-yr low diversity rotations (LDR) (continuous triticale (T-T_LDR) and triticale-wheat (Triticum aestivum L.) (T-W_LDR)); three, 2-yr moderate diversity rotations (MDR) (triticale-field pea (T-P_MDR), triticale-canola (T-C_MDR), and a triticale: field pea intercrop (T- in P_MDR)); and one, 3-yr high diversity rotation (HDR) (canola-triticale-field pea (C-T-P_HDR)). The study was established in Lethbridge, Alberta (irrigated and rainfed); Swift Current (rainfed) and Canora (rainfed), Saskatchewan, Canada; and carried out from 2008 to 2014. Triticale grain yield for the 3-yr HDR was superior over the LDR rotations and the MDR triticale-field pea system; however, results were similar for triticale-canola, and removal of canola from the system caused a yield drag in triticale. Triticale biomass was superior for the 3-yr HDR. Moreover, along with improved triticale grain yield, the 3-yr HDR provided greater yield stability across environments. High rotational diversity (C-T-P_HDR) resulted in the highest soil microbial community and soil carbon concentration, whereas continuous triticale provided the lowest. Net economic returns were also superior for C-T-P_HDR ($670 ha–1) and the lowest for T-W_LDR ($458 ha–1). Overall, triticale responded positively to increased rotational diversity and displayed greater stability with the inclusion of field pea, leading to improved profitability and sustainability of the system.
Authors:A. Sarkar, R. C. Das, MD H. Rashid, M. Ali, M. S. Islam, T. Asaeda, and Q. Wang
Isolates of Pestalozzia theae Saw. and Trichoderma spp. were collected from Bangladesh Tea Research Institute (BTRI) farm area, Bangladesh. The cultural morphology and antagonistic potentiality of Trichoderma spp. against grey blight pathogen Pestalozzia theae was studied for tea cultivation. The antagonistic potentiality of Trichoderma spp., against Pestalozzia theae showed maximum (inhibition 84.45±0.77%) after 72 hrs of inoculation under in vitro condition followed by 76.02±3.50% after 24 hrs of inoculation. This study revealed that Trichoderma strain was highly effective to control Pestalozzia theae, the causal agent of grey blight disease of tea.
Authors:G. Vida, M. Cséplő, G. Gulyás, I. Karsai, T. Kiss, J. Komáromi, E. László, K. Puskás, Z. Wang, C. Pace, Z. Bedő, L. Láng, and O. Veisz
Among the factors which determine yield reliability an important role is played by disease resistance. One of the breeding aims in the Martonvásár institute is to develop wheat varieties with resistance to major diseases. The winter wheat varieties bred in Martonvásár are examined in artificially inoculated nurseries and greenhouses for resistance to economically important pathogens. The effectiveness of designated genes for resistance to powdery mildew and leaf rust has been monitored over a period of several decades. None of the designated major resistance genes examined in greenhouse tests is able to provide complete resistance to powdery mildew; however, a number of leaf rust resistance genes provide full protection against pathogen attack (Lr9, Lr19, Lr24, Lr25, Lr28 and Lr35). In the course of marker-assisted selection, efficient resistance genes (Lr9, Lr24, Lr25 and Lr29) have been incorporated into Martonvásár wheat varieties. The presence of Lr1, Lr10, Lr26, Lr34 and Lr37 in the Martonvásár gene pool was identified using molecular markers. New sources carrying alien genetic material have been tested for powdery mildew and leaf rust resistance. Valuable Fusarium head blight resistance sources have been identified in populations of old Hungarian wheat varieties. Species causing leaf spots (Pyrenophora tritici-repentis, Septoria tritici and Stagonospora nodorum) have gradually become more frequent over the last two decades. Tests on the resistance of the host plant were begun in Martonvásár four years ago and regular greenhouse tests on seedlings have also been initiated.