scholarly journals Root and Shoot Traits of Spring Wheat Cultivars with Wild-Type and Semi-Dwarf Rht Alleles at Early and Late Growth Stages

Author(s):  
Hayati Akman ◽  
Philip Bruckner

Roots play an important role in improving crop yield by affecting the amount of water uptake and nutrient acquisition. The objective of this study was to characterize variability in root and above-ground characteristics among three diverse semi-dwarf spring wheat cultivars, ‘Vida’, ‘Oneal’ and ‘Duclair’ and a wild-type cultivar, ‘Scholar’ at early and late growth stages in a greenhouse. Plants were grown in 45-cm long tree pots in a greenhouse under optimal growth conditions. As soil-less media, a mixture of peat (70%) and perlite (30%) was used. Plants were harvested at tillering (GS25-26) with 5-6 tillers, booting (GS43-45), and maturity (GS92). Root and shoot traits indicated significant variability among wild-type and semi-dwarf spring wheat cultivars at those growth stages. The study results showed that root mass per plant at tillering, booting, and maturity ranged from 0.10 to 0.14 g, 0.47 to 0.9 g, and 0.55 to 0.85 g, respectively, while shoot mass per plant varied from 1.7 to 2.5 g, 6.5 to 10.7 g, and 21.2 to 24.5 g, respectively. From booting to maturity, root mass was relatively constant, however, shoot mass increased considerably. Moreover, the average root mass of semi-dwarf spring wheat cultivars was 37% lower at booting and 30% lower at maturity compared to the wild-type cultivar, even though there was no significant variation among the cultivars at the early growth stage. Based on the results of the variability identified in this research, wild-type cultivar, Scholar can be evaluated for the improvement of genotypes with superior root system in breeding programs.

Author(s):  
Hayati Akman

Knowledge of root architecture is significant since it influences on pathways from, photosynthesis products, water and nutrient movement. This study purposed to elucidate root mass, root length, root/shoot ratio, root/total mass ratio and above-ground characteristics in Vicia pannonica Crantz., Carthamus tinctorius L. and Pisum sativum ssp. arvense L. with taproot and Triticum aestivum L., Hordeum vulgare L. conv. distichon, X Triticosecale Wittmack, Avena sativa L. and Secale cereale L. with fibrous roots at 200 cm long tubes under field-grown condition. Crop harvesting is based on early and late growth stages of cereal crops. The results indicated that winter field crops had a wide range of differences with regard to root and above-ground traits at both growth stages. The root traits of field crop species varied considerably from 0.3 to 5.9 g and 2.4 to 11.9 g for root mass and 84.7 to 127.7 cm and 84.5 to 166 cm for root length at early and late growth stages respectively, while shoot mass was between 0.3–5.7 g and 5.5–29.8 g. Furthermore, the percentage distribution of root mass accumulated in 0-20 cm root length at early and late growth stages, ranged between 52.3 to 81.4 % and 27.7 to 75.2 %, respectively. The findings showed that crops with taproot had less root and shoot mass and shorter root length than cereals with fibrous roots at both growth stages. This study also significantly advances our understanding of root-shoot competition by comparing the agronomical traits of winter field crops with tap and fibrous roots at different growth stages.


2016 ◽  
Vol 64 (22) ◽  
pp. 4545-4555 ◽  
Author(s):  
Thomas Etzerodt ◽  
Rene Gislum ◽  
Bente B. Laursen ◽  
Kirsten Heinrichson ◽  
Per L. Gregersen ◽  
...  

2003 ◽  
Vol 141 (2) ◽  
pp. 129-147 ◽  
Author(s):  
G. S. McMASTER ◽  
W. W. WILHELM

Understanding and predicting small-grain cereal development is becoming increasingly important in enhancing management practices. Recent efforts to improve phenology submodels in crop simulations have focused on incorporating developmental responses to water stress and interpreting and understanding thermal time. The objectives of the present study were to evaluate data from three experiments to (a) determine the qualitative and quantitative response of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) to water stress and (b) ascertain where in space to measure temperature, to provide information required to improve phenological submodels. The first experiment tested the phenological responses of 12 winter wheat cultivars to water stress for two seasons at two sites. The second experiment tested the timing of water stress on spring barley phenological responses for 2 years. In a third experiment, soil near the shoot apex of field-grown spring wheat was heated to 3°C above ambient soil temperature for three planting dates in each of 2 years, to test whether it is better to use soil or air temperature in calculating thermal time. The general response of wheat and barley to water stress was to reach growth stages earlier (i.e. to hasten development). The most significant response was for the grain filling period. Water stress had little effect on jointing and flag leaf complete/booting growth stages. Thermal time to jointing was highly variable across locations. However, thermal time to subsequent growth stages was very consistent both within and across locations. The winter wheat cultivars tested followed this general response across site-years, but inconsistencies were found, suggesting a complicated genotype by environment (G×E) interaction that makes improving phenology submodels for all cultivars difficult. The G×E interaction was most prominent for anthesis (A) and maturity (M) growth stages. Results of heating the soil at the shoot apex depth were completely unexpected: heating the soil did not speed spring wheat phenological development. These results, and others cited, suggest caution in allocating effort and resources to measuring or estimating soil temperature rather than relying on readily available air temperature as a means of universally improving phenology submodels. These results help quantify the response of wheat to water stress and thermal time for improving crop simulation models and management.


2008 ◽  
Vol 32 (5) ◽  
pp. 1977-1986 ◽  
Author(s):  
Adelson Paulo Araújo ◽  
Marcelo Grandi Teixeira

Shoot biomass is considered a relevant component for crop yield, but relationships between biological productivity and grain yield in legume crops are usually difficult to establish. Two field experiments were carried out to investigate the relationships between grain yield, biomass production and N and P accumulation at reproductive stages of common bean (Phaseolus vulgaris) cultivars. Nine and 18 cultivars were grown on 16 m² plots in 1998 and 1999, respectively, with four replications. Crop biomass was sampled at four growth stages (flowering R6, pod setting R7, beginning of pod filling R8, and mid-pod filling R8.5), grain yield was measured at maturity, and N and P concentrations were determined in plant tissues. In both years, bean cultivars differed in grain yield, in root mass at R6 and R7 stages, and in shoot mass at R6 and R8.5, whereas at R7 and R8 differences in shoot mass were significant in 1998 only. In both years, grain yield did not correlate with shoot mass at R6 and R7 and with root mass at R6. Grain yield correlated with shoot mass at R8 in 1999 but not in 1998, with shoot mass at R8.5 and with root mass at R7 in both years. Path coefficient analysis indicated that shoot mass at R8.5 had a direct effect on grain yield in both years, that root mass at R7 had a direct effect on grain yield in 1998, and that in 1999 the amounts of N and P in shoots at R8.5 had indirect effects on grain yield via shoot mass at R8.5. A combined analysis of both experiments revealed that biomass accumulation, N and P in shoots at R6 and R7 as well as root mass at R6 were similar in both years. In 1998 however bean accumulated more root mass at R7 and more biomass and N and P in shoots at R8 and R8.5, resulting in a 57 % higher grain yield in 1998. This indicates that grain yield of different common bean cultivars is not intrinsically associated with vegetative vigor at flowering and that mechanisms during pod filling can strongly influence the final crop yield. The establishment of a profuse root system during pod setting, associated with the continuous N and P acquisition during early pod filling, seems to be relevant for higher grain yields of common bean.


2019 ◽  
Vol 124 (6) ◽  
pp. 993-1006 ◽  
Author(s):  
Long Li ◽  
Zhi Peng ◽  
Xinguo Mao ◽  
Jingyi Wang ◽  
Xiaoping Chang ◽  
...  

Abstract Background and Aims Root system morphology is important for sustainable agriculture, but the genetic basis of root traits and their relationship to shoot traits remain to be elucidated. The aim of the present study was to dissect the genetic basis of root traits at late growth stages and its implications on shoot traits in wheat. Methods Among 323 wheat accessions, we investigated phenotypic differences in root traits at booting and mid-grain fill stages in PVC tubes, shoot traits including plant height (PH), canopy temperature (CT) and grain yield per plant (YPP) in a field experiment, and performed a genome-wide association study with a Wheat 660K SNP Array. Key Results Deep-rooted accessions had lower CT and higher YPP than those with shallow roots, but no significant relationship was identified between root dry weight and shoot traits. Ninety-three significantly associated loci (SALs) were detected by the mixed linear model, among which three were hub SALs (Co-6A, Co-6B and Co-6D) associated with root depth at both booting and mid-grain fill stages, as well as CT and YPP. Minirhizotron system scanning results suggested that the causal genes in the three SALs may regulate root elongation in the field. The heritable independence between root depth and PH was demonstrated by linkage disequilibrium analysis. The YPP was significantly higher in genotypes which combined favourable marker alleles (FMAs) for root depth and PH, suggesting that a deep root and shorter plant height are suitable traits for pyramiding target alleles by molecular marker-assisted breeding. Conclusions These results uncovered promising genomic regions for functional gene discovery of root traits in the late growth period, enhanced understanding of correlation between root and shoot traits, and will facilitate intensive study on root morphology and breeding through molecular design.


2021 ◽  
Vol 22 (21) ◽  
pp. 11494
Author(s):  
Bartosz Jablonski ◽  
Andrzej Bajguz ◽  
Joanna Bocian ◽  
Waclaw Orczyk ◽  
Anna Nadolska-Orczyk

The influence of silenced TaCKX1 and TaCKX2 on coexpression of other TaCKX gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation of TaCKX GFM expression in which silencing of TaCKX1 upregulated expression of TaCKX2 genes and vice versa. Additionally, downregulation of TaCKX2 highly upregulated the expression of TaCKX5 and TaNAC2-5A. In contrast, expression of these genes in silenced TaCKX1 was downregulated. Silenced TaCKX1 T2 lines with expression decreased by 47% had significantly higher thousand grain weight (TGW) and seedling root mass. Silenced TaCKX2 T2 lines with expression of TaCKX2.2.1 and TaCKX2.2.2 decreased by 33% and 30%, respectively, had significantly higher chlorophyll content in flag leaves. TaCKX GFM expression, phytohormone metabolism and phenotype were additionally modified by Agrobacterium-mediated transformation. Two novel phytohormones, phenylacetic acid (PAA) and topolins, lack of gibberellic acid (GA) and changed phytohormone contents in the 7 days after pollination (DAP) spikes of the awned-spike cultivar compared to a previously tested, awnless one, were detected. We documented that major mechanisms of coregulation of the expression of TaCKX GFMs were similar in different spring wheat cultivars, but, depending on content and composition of phytohormones, regulation of yield-related traits was variously impacted.


2019 ◽  
Vol 144 (6) ◽  
pp. 394-404 ◽  
Author(s):  
Limeng Xie ◽  
Patricia Klein ◽  
Kevin Crosby ◽  
John Jifon

Roots impact plants’ capacity to absorb water and nutrients and thus play a vital role in tolerance to drought, salinity, and nutrient stress. In tomato (Solanum lycopersicum) breeding programs, wild tomato species have been commonly used to increase disease resistance and fruit quality and yield. However, tomato has seldom been bred for water/nutrient use efficiency or resilience to abiotic stress. Meanwhile, little knowledge of the genetic control of root traits in tomato is available. In this study, a mapping population consisting of 181 F2 progenies derived from a cross between an advanced breeding line RvT1 (S. lycopersicum) and a wild species Lche4 (Solanum cheesmaniae) was evaluated for root and shoot traits in the greenhouse. Root phenotypes were studied for the early seedling stage. Heritability estimates show that root traits are moderately or highly heritable. Root mass was highly correlated with root size (length, surface area, and volume). Shoot mass and chlorophyll content (SPAD) were moderately correlated with root mass and size. Genotyping-by-sequencing was applied to discover single nucleotide polymorphism (SNP) markers. Seven hundred and forty-two SNPs were successfully mapped, and a medium-dense linkage map was created that covered 1319.47 centimorgans (cM) with an average distance of 1.78 cM between adjacent markers. Using composite interval mapping, multiple quantitative trait loci (QTL) mapping and nonparametric mapping, 29 QTLs were identified for 12 root and shoot traits on eight chromosomes. Those QTLs of major and minor effect were involved in the differences among the F2 population. Two QTL hotspot regions associated with root mass, size, shoot mass and SPAD were identified on chromosomes 1 and 4, which was consistent with the correlation among traits. Five QTLs for shoot length and eight QTLs for SPAD were accounting for 40.01% and 55.53% of the phenotypic variation. Two QTLs were associated with 18.26% of the total variation for specific root length. The wild parent Lche4 has been characterized as a potential genetic donor of higher specific root length and might be a good parent to modify the root system of cultivated tomato.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Jackline Abu-Nassar ◽  
Maor Matzrafi

Solanum rostratum Dunal is an invasive weed species that invaded Israel in the 1950s. The weed appears in several germination flashes, from early spring until late summer. Recently, an increase in its distribution range was observed, alongside the identification of new populations in the northern part of Israel. This study aimed to investigate the efficacy of herbicide application for the control of S. rostratum using two field populations originated from the Golan Heights and the Jezreel Valley. While minor differences in herbicide efficacy were recorded between populations, plant growth stage had a significant effect on herbicide response. Carfentrazone-ethyl was found to be highly effective in controlling plants at both early and late growth stages. Metribuzin, oxadiazon, oxyfluorfen and tembutrione showed reduced efficacy when applied at later growth stage (8–9 cm height), as compared to the application at an early growth stage (4–5 cm height). Tank mixes of oxadiazon and oxyfluorfen with different concentrations of surfactant improved later growth stage plant control. Taken together, our study highlights several herbicides that can improve weed control and may be used as chemical solutions alongside diversified crop rotation options. Thus, they may aid in preventing the spread and further buildup of S. rostratum field populations.


1992 ◽  
Vol 12 (9) ◽  
pp. 3827-3833 ◽  
Author(s):  
T H Adams ◽  
W A Hide ◽  
L N Yager ◽  
B N Lee

In contrast to many other cases in microbial development, Aspergillus nidulans conidiophore production initiates primarily as a programmed part of the life cycle rather than as a response to nutrient deprivation. Mutations in the acoD locus result in "fluffy" colonies that appear to grow faster than the wild type and proliferate as undifferentiated masses of vegetative cells. We show that unlike wild-type strains, acoD deletion mutants are unable to make conidiophores under optimal growth conditions but can be induced to conidiate when growth is nutritionally limited. The requirement for acoD in conidiophore development occurs prior to activation of brlA, a primary regulator of development. The acoD transcript is present both in vegetative hyphae prior to developmental induction and in developing cultures. However, the effects of acoD mutations are detectable only after developmental induction. We propose that acoD activity is primarily controlled at the posttranscriptional level and that it is required to direct developmentally specific changes that bring about growth inhibition and activation of brlA expression to result in conidiophore development.


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