Effects of uniconazole or ethephon foliar application on culm mechanical strength and lignin metabolism, and their relationship with lodging resistance in winter wheat

2020 ◽  
Vol 71 (1) ◽  
pp. 12 ◽  
Author(s):  
Irshad Ahmad ◽  
Muhammad Kamran ◽  
Ziyan Guo ◽  
Xiangping Meng ◽  
Shahzad Ali ◽  
...  

Lodging in plants is an important constraint that leads to yield losses and cause problems with mechanical harvesting. This research was aimed at determining the effects of foliar application of uniconazole or ethephon on lignin metabolism, characteristics of second basal internode and their relationship with lodging resistance in winter wheat (Triticum aestivum L.). In separate experiments, uniconazole was sprayed on the foliage at concentrations of 0, 15, 30 and 45 mg L–1, and ethephon at concentrations of 0, 50, 75 and 100 mg L–1 at the four-leaf stage. Foliar application of uniconazole or ethephon significantly reduced the lodging rate by increasing the lignin content and optimising basal-internode characteristics. Lignin content was significantly positively correlated with breaking strength, and negatively correlated with lodging rate, whereby the higher lignin content in the second basal internode significantly improved the lodging resistance and reduced the lodging rate in the wheat crop. Foliar application of uniconazole or ethephon also increased the breaking strength, internode diameter, wall thickness and internode plumpness of the second basal internode; maximum values were obtained with uniconazole at 30 mg L–1 and with ethephon at 75 mg L–1. Grain yield, lignin content and lignin-related enzyme activities of phenylalanine ammonia-lyase, tyrosine ammonia-lyase, cinnamyl alcohol dehydrogenase and peroxidase were all significantly improved with the foliar application of uniconazole or ethephon. These results suggest that lignin content in the second basal internode in wheat was closely related with lodging resistance. Foliar application of uniconazole or ethephon at the four-leaf stage reduced the lodging rate, and the concentration showing the greatest effects was 30 mg L–1 for uniconazole or 75 mg L–1 for ethephon.

2021 ◽  
Vol 182 (1) ◽  
pp. 33-40
Author(s):  
I. V. Karkhardin ◽  
A. A. Konovalov ◽  
N. P. Goncharov

Background.Winter crops are the most productive component of agricultural biocenoses. In Russia, winter wheat suffers the greatest losses in winter, so a search for traits marking high or low winter hardiness in autumn-sown genotypes, including improved cultivars, is needed to assess their potential for overwintering. One of such markers of high winter hardiness is an increased lignin content in plant tissues. The terminal enzyme in the phenylpropanoid pathway of metabolism, wherein lignin components are formed, is cinnamyl-alcohol dehydrogenase (CAD, EC 1.1.1.195). In plants, the CAD enzyme is one of the links in the aromatic metabolism, which generates, in addition to lignin, a number of aromatic compounds, such as lignans, aromatic glycosides, etc. Many of these compounds, like lignin, contain chromophore groups and are capable of autofluorescence.Correlations of the genotypes that incorporate CAD1-F with overwintering are studied in this work.Materials and methods.The winter bread wheat cultivars ‘Zitnica’ (Yugoslavia) and ‘Novosibirskaya 9’ (ICG SB RAS, Russia), contrasting in winter hardiness and CAD isozyme spectra, their hybrids, and 28 improved winter cultivars developed in Krasnodar were selected for the study. Fluorescence analysis of 28 winter wheat cultivars was also performed. Correlation coefficients between fluorescence and frost tolerance were calculated using the results of the analysis of 7 most contrasting cultivars.Conclusions. The tested winter bread wheat genotypes demonstrated the interplay between CAD1-F and successful overwintering: a correlation was found in the genotypes carrying the 00 CAD1-F allele with higher percentage of overwintered plants. This dependence was not observed in every season. The analysis of seedling sections for fluorescence can also be used for preliminary assessment of winter tolerance in winter bread wheat under laboratory conditions.


2017 ◽  
Vol 68 (4) ◽  
pp. 349 ◽  
Author(s):  
Bohong Tian ◽  
Yanli Liu ◽  
Lixin Zhang ◽  
Hongjie Li

Foxtail millet (Setaria italica (L.) Beauv.) is a soft-stemmed summer cereal crop that is grown at a high crop density; however, stem lodging is recognised as a serious yield-limiting factor. The stem-breaking strength of the third to fifth basal internodes has previously been identified as the most important factor in determining the lodging resistance of foxtail millet. We measured variation in stem-breaking strength, length and weight of these internodes at different developmental stages and in response to different crop densities by using foxtail millet cultivars that differed in lodging resistance. The stem-breaking strength of the third internode was greater than of the fourth and fifth internodes, which had comparable stem-breaking strengths; this result was independent of genotype and developmental stage. The stem-breaking strengths of the three internodes were significantly correlated with each other and linearly related across different developmental stages and crop densities. The stem-breaking strength of the three internodes at hard dough stage (Zadoks growth stage Z87, at 30 days after flowering) was less than at other developmental stages in the lodging-resistant genotypes. Stem-breaking strength for the three internodes was correlated with fresh weight (FW) and dry weight (DW) per cm. The variation of FW and DW per cm of the internodes in response to crop density was attributed to the change of FW and DW of the corresponding internodes, rather than to variation in their length. Results from this study showed that the fourth or fifth basal internode was more prone to lodging than the third basal internode because of their lesser stem-breaking strength. Crop density linearly influenced the stem-breaking strength of the three basal internodes. Reducing crop density enhanced stem-breaking strength of third to fifth internodes, which may reduce the risk of stem lodging in this crop. Based on the findings, the stem-breaking strength of the fourth or fifth basal internode measured at the late grain-filling stage from Z77 (late milk) to Z87 (hard dough) differentiated stem-breaking strength, the most important stem lodging associated parameter, in the foxtail millet genotypes.


2001 ◽  
Vol 24 (1-4) ◽  
pp. 235-241 ◽  
Author(s):  
Rose Lucia Braz Ramos ◽  
Francisco Javier Tovar ◽  
Ricardo Magrani Junqueira ◽  
Fabiane Borges Lino ◽  
Gilberto Sachetto-Martins

Lignins are phenolic polymers found in the secondary wall of plant conductive systems where they play an important role by reducing the permeability of the cell wall to water. Lignins are also responsible for the rigidity of the cell wall and are involved in mechanisms of resistance to pathogens. The metabolic routes and enzymes involved in synthesis of lignins have been largely characterized and representative genes that encode enzymes involved in these processes have been cloned from several plant species. The synthesis of lignins is liked to the general metabolism of the phenylpropanoids in plants, having enzymes (e.g. phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H) and caffeic acid O-methyltransferase (COMT)) common to other processes as well as specific enzymes such as cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD). Some maize and sorghum mutants, shown to have defective in CAD and/or COMT activity, are easier to digest because they have a reduced lignin content, something which has motivated different research groups to alter the lignin content and composition of model plants by genetic engineering try to improve, for example, the efficiency of paper pulping and digestibility. In the work reported in this paper, we have made an inventory of the sugarcane expressed sequence tag (EST) coding for enzymes involved in lignin metabolism which are present in the sugarcane EST genome project (SUCEST) database. Our analysis focused on the key enzymes ferulate-5-hydroxylase (F5H), caffeic acid O-methyltransferase (COMT), caffeoyl CoA O-methyltransferase (CCoAOMT), hydroxycinnamate CoA ligase (4CL), cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD). The comparative analysis of these genes with those described in other species could be used as molecular markers for breeding as well as for the manipulation of lignin metabolism in sugarcane.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1223
Author(s):  
Mojde Sedaghat ◽  
Yahya Emam ◽  
Ali Mokhtassi-Bidgoli ◽  
Saeid Hazrati ◽  
Claudio Lovisolo ◽  
...  

Strigolactones (SLs) have been implicated in many plant biological and physiological processes, including the responses to abiotic stresses such as drought, in concert with other phytohormones. While it is now clear that exogenous SLs may help plants to survive in harsh environmental condition, the best, most effective protocols for treatment have not been defined yet, and the mechanisms of action are far from being fully understood. In the set of experiments reported here, we contrasted two application methods for treatment with a synthetic analog of SL, GR24. A number of morphometric, physiological and biochemical parameters were measured following foliar application of GR24 or application in the residual irrigation water in winter wheat plants under irrigated and drought stress conditions. Depending on the concentration and the method of GR24 application, differentiated photosynthesis and transpiration rate, stomatal conductance, leaf water potential, antioxidant enzyme activities and yield in drought conditions were observed. We present evidence that different methods of GR24 application led to increased photosynthesis and yield under stress by a combination of drought tolerance and escape factors, which should be considered for future research exploring the potential of this new family of bioactive molecules for practical applications.


2021 ◽  
Vol 13 (12) ◽  
pp. 6876
Author(s):  
Yuetao Zuo ◽  
Xueyue Zhang ◽  
Shiyu Zuo ◽  
Xiaosong Ren ◽  
Zhaoyue Liu ◽  
...  

In response to the production crisis caused by a winter feed shortage due to the rapid development of the animal husbandry industry, winter rye 001 was selected to study differences in stalk and senescence characteristics in yield formation in cold regions. Five density treatments were established in a randomized design as 225 × 104 plant·hm−2 (D1), 275 × 104 plant·hm−2 (D2), 325 × 104 plant·hm−2 (D3), 375 × 104 plant·hm−2 (D4), and 425 × 104 plant·hm−2 (D5). Stem characteristics, SOD activity, POD activity, MDA content, and differences in yield and feeding quality under different population densities were analyzed. The plant height, center of gravity, and stem basal internode length showed an increasing trend with an increase in planting density. The stem wall thickness, diameter, strength, and lodging resistance indices decreased. At 275 × 104 plants·hm−2, the rye crude protein content was the highest while neutral washing fiber and acid washing fiber were the lowest, and feed quality was the best. With an increase in density, spike number, grain number per spike, and thousand-grain weight first increased and then decreased. We concluded that the yield and feeding quality were best when the basic seedling was at 275 × 104 plants hm−2.


2021 ◽  
Vol 20 (8) ◽  
pp. 2077-2089
Author(s):  
Bin LI ◽  
Fei GAO ◽  
Bai-zhao REN ◽  
Shu-ting DONG ◽  
Peng LIU ◽  
...  

2012 ◽  
Vol 175 (1) ◽  
pp. 142-151 ◽  
Author(s):  
Md. Rezaul Karim ◽  
Yue-Qiang Zhang ◽  
Rong-Rong Zhao ◽  
Xin-Ping Chen ◽  
Fu-Suo Zhang ◽  
...  

2012 ◽  
Vol 29 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Drew J. Lyon ◽  
Gary W. Hergert

AbstractOrganic farming systems use green and animal manures to supply nitrogen (N) to their fields for crop production. The objective of this study was to evaluate the effect of green manure and composted cattle manure on the subsequent winter wheat (Triticum aestivumL.) crop in a semiarid environment. Dry pea (Pisum sativumL.) was seeded in early April and terminated at first flower in late June. Composted cattle manure was applied at 0, 11.2 or 22.5 Mg ha−1just prior to pea termination. Winter wheat was planted in mid September following the green manure or tilled summer fallow. No positive wheat response to green manure or composted cattle manure was observed in any of the 3 years of the study. In 2 of the 3 years, wheat yields and grain test weight were reduced following green manure. Green manure reduced grain yields compared with summer fallow by 220 and 1190 kg ha−1in 2009 and 2010, respectively. This may partially be explained by 40 and 47 mm less soil water at wheat planting following peas compared with tilled summer fallow in 2008 and 2009, respectively. Also, in 2008 and 2009, soil nitrate level averaged 45 kg ha−1higher for black fallow compared with green manure fallow when no compost was added. Organic growers in the semiarid Central Great Plains will be challenged to supply N fertility to their winter wheat crop in a rapid and consistent manner as a result of the inherently variable precipitation. Growers may need to allow several years to pass before seeing the benefits of fertility practices in their winter wheat cropping systems.


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