The relationship between flag leaf senescence and grain yield of some durum wheat varieties under drought stress during grain filling period

Durum wheat performance in the Mediterranean climate is limited when water scarcity occurs before and during anthesis. The present research was performed to determine the effect of drought stress on several physiological and agro-morphological traits in 17 durum wheat genotypes under two conditions (control and drought) over two years. The results of analysis of variance indicated that the various durum wheat genotypes responded differently to drought stress. Drought stress significantly reduced the grain filling period, plant height, peduncle length, number of spikes per plot, number of grains per spike, thousand grains weight, grain yield, biomass, and harvest index in all genotypes compared to the control condition. The heatmap-based correlation analysis indicated that grain yield was positively and significantly associated with phenological characters (days to heading, days to physiological maturity, and grain filling period), as well as number of spikes per plant, biomass, and harvest index under drought conditions. The yield-based drought and susceptible indices revealed that stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), and harmonic mean (HM) were positively and significantly correlated with grain yields in both conditions. Based on the average of the sum of ranks across all indices and a three-dimensional plot, two genotypes (G9 and G12) along with the control variety (G1) were identified as the most tolerant genotypes. Among the investigated genotypes, the new breeding genotype G12 showed a high drought tolerance and yield performance under both conditions. Hence, this genotype can be a candidate for further multi-years and locations test as recommended for cultivation under rainfed conditions in arid and semi-arid regions.

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Effects of successive applications of maneb and benomyl on growth and yield of five wheat varieties of different heights.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v21i4.17243 ◽

1973 ◽

Vol 21 (4) ◽

pp. 282-296

Author(s):

J.H.J. Spiertz

Keyword(s):

Grain Yield ◽

Flag Leaf ◽

Combined Treatment ◽

Grain Filling ◽

Growth And Yield ◽

Septoria Tritici ◽

Wheat Varieties ◽

Leptosphaeria Nodorum ◽

Culm Length ◽

Grain Filling Period

Wheat cv. Juliana (culm length 117 cm), Manella (82 cm), Lely (80 cm), Mex-cross (69 cm) and Gaines (79 cm) were sprayed twice before flowering with 2 kg maneb/ha and twice after flowering with 1 kg benomyl/ha. Combined treatment greatly delayed the spread of Septoria tritici and S. nodorum in the crop, the flag leaf remained green longer, the grain filling period was lengthened, and the growth rate of the grain between the milk stage and the dough stage was increased from 204 to 230 kg/ha day; effects were greater in the susceptible cultivars Lely and Gaines. Increases in grain yield were 14, 23, 32, 16 and 42% for the 5 cultivars, respectively. The green area of the flag leaf accounted for 85% of the variance in grain yield. The degree of disease infection was not significantly correlated with culm length or amount of leaf area. ADDITIONAL ABSTRACT: Spraying with maneb at 2 kg/ha twice before flowering and with benomyl at 1 kg/ha twice after flowering greatly delayed the spread of Septoria tritici and S. [Leptosphaeria] nodorum and increased yields, particularly in the 2 susceptible cvs. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Characterisation of grain yield and nitrogen level in relation to flag leaf senescence of wheat varieties

Physiologia Plantarum ◽

10.1111/j.1399-3054.1986.tb05958.x ◽

1986 ◽

Vol 66 (3) ◽

pp. 503-508 ◽

Cited By ~ 8

Author(s):

I. Ma. Martin del Molino ◽

M. Ulloa ◽

R. Martinez-Carrasco ◽

P. Perez

Keyword(s):

Grain Yield ◽

Leaf Senescence ◽

Flag Leaf ◽

Nitrogen Level ◽

Wheat Varieties

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Rate and duration of grain filling in relation to flag leaf senescence and grain yield in spring wheat (Triticum aestivum) exposed to different concentrations of ozone

Physiologia Plantarum ◽

10.1111/j.1399-3054.2000.1100311.x ◽

2008 ◽

Vol 110 (3) ◽

pp. 366-375 ◽

Cited By ~ 1

Author(s):

Johanna Gelang ◽

Håkan Pleijel ◽

Ebe Sild ◽

Helena Danielsson ◽

Suhaila Younis ◽

...

Keyword(s):

Triticum Aestivum ◽

Grain Yield ◽

Leaf Senescence ◽

Spring Wheat ◽

Flag Leaf ◽

Grain Filling

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Nitrogen deficiency regulates premature senescence by modulating flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling

Journal of Genetic Engineering and Biotechnology ◽

10.1186/s43141-021-00275-3 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Shamsu Ado Zakari ◽

Syed Hassan Raza Zaidi ◽

Mustapha Sunusi ◽

Kabiru Dawaki Dauda

Keyword(s):

Grain Yield ◽

Leaf Senescence ◽

Flag Leaf ◽

Grain Filling ◽

Sugar Concentration ◽

Premature Senescence ◽

N Supply ◽

Ros Homeostasis ◽

N Assimilation ◽

N Deficiency

Abstract Background Leaf senescence occurs in an age-dependent manner, but the rate and timing of leaf senescence may be influenced by various biotic and abiotic factors. In the course of stress, the function, composition, and different components of photosynthetic apparatus occur to be synthesized homogeneously or degraded paradoxically due to different senescence-related processes. Nitrogen (N) deficiency is one of the critical environmental factors that induce leaf senescence, and its incidence may curtail leaf photosynthetic function and markedly alter the genetic information of plants that might result in low grain yield. However, the physiological and genetic mechanism underlying N deficiency regulates premature senescence, and flag leaf function, ROS homeostasis, and intercellular sugar concentration in rice during grain filling are not well understood. In this paper, Zhehui7954 an excellent indica restorer line (wildtype) and its corresponding mutant (psf) with the premature senescence of flag leaves were used to study the effect of different N supplies in the alteration of physiological and biochemical components of flag leaf organ and its functions during grain filling. Results The results showed that the psf mutant appeared to be more susceptible to the varying N supply levels than WT. For instance, the psf mutant showed considerably lower Pn, Chl a, Chl b, and Car contents than its WT. N deficiency (LN) decreased leaves photosynthetic activities, N metabolites, but significantly burst O2•−, H2O2, and relative conductivity (R1/R2) concentrations, which was consistent with the expression levels of senescence-associated genes. Sucrose, glucose, and C/N ratio concentrations increased with a decrease in N level, which was closely associated with N and non-structural carbohydrate translocation rates. Increases in POD activity were positively linked with the senescence-related enhancement of ROS generation under LN conditions, whereas, SOD, CAT, and APX activities showed opposite trends. High N (HN) supply significantly inhibits the transcripts of carbohydrate biosynthesis genes, while N assimilation gene transcripts gradually increased along with leaf senescence. The psf mutant had a relatively higher grain yield under HN treatment than LN, while WT had a higher grain yield under MN than HN and LN. Conclusions This work revealed that the C/N ratio and ROS undergo a gradual increase driven by interlinking positive feedback, providing a physiological framework connecting the participation of sugars and N assimilation in the regulation of leaf senescence. These results could be useful for achieving a higher yield of rice production by appropriate N supply and plant senescence regulation.

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Correlation and path analysis in recombinant inbred lines (RILs) of wheat (Trticum aestivum L.)

Journal of Applied and Natural Science ◽

10.31018/jans.v8i2.880 ◽

2016 ◽

Vol 8 (2) ◽

pp. 826-832

Author(s):

Ramesh Ramesh ◽

Shailesh Marker ◽

S. Muniswamy ◽

Yamanura Yamanura

Keyword(s):

Grain Yield ◽

Recombinant Inbred ◽

Recombinant Inbred Lines ◽

Flag Leaf ◽

Correlation Coefficients ◽

Grain Filling ◽

Inbred Lines ◽

Spike Length ◽

Grain Filling Period ◽

Selection Of

Correlation and path coefficient analysis were studied in 22 heat tolerant Recombinant Inbred Lines (RILs) of wheat. Analysis of variance revealed the significant difference among genotypes for all the characters. Suggested that there was ample scope for selection of promising RILs for yield improvement. A wide range of variability was exhibited by most of the traits. The results of correlation studies indicated that genotypic correlation coefficients were higher in magnitude than their corresponding phenotypic correlation coefficients for all the traits which indicated that association among these characters was under genetic control and indicating the preponderance of genetic variance in expression of characters. Grain yield per plant had high, significant and positive association with number of grains per spike, spike weight, spike length, canopy temperature depression, tillers per plant, grain filling period and chlorophyll content both at genotypic and phenotypic levels indicating that these traits were main yield attributing traits. Path analysis revealed that grains per spike, tillers per plant, spike length, had the highest positive direct effect on grain yield followed by flag leaf length, flag leaf width, days 50% heading, plant height, grain filling period, membrane stability and days to maturity at genotypic level. The selection of characters such as grains per spike, tillers per plant, spike length and spike weight would be helpful for further improvement in RILs of wheat.

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Paclobutrazol Application Favors Yield Improvement of Maize Under Semiarid Regions by Delaying Leaf Senescence and Regulating Photosynthetic Capacity and Antioxidant System During Grain-Filling Stage

Agronomy ◽

10.3390/agronomy10020187 ◽

2020 ◽

Vol 10 (2) ◽

pp. 187 ◽

Cited By ~ 3

Author(s):

Muhammad Kamran ◽

Shakeel Ahmad ◽

Irshad Ahmad ◽

Izhar Hussain ◽

Xiangping Meng ◽

...

Keyword(s):

Grain Yield ◽

Leaf Senescence ◽

Photosynthetic Rate ◽

Grain Filling ◽

Yield Improvement ◽

Chlorophyll Contents ◽

Maize Seeds ◽

Kernel Weights ◽

Ros Burst ◽

Grain Filling Period

In the present study, we examined the potential role of paclobutrazol in delaying leaf senescence, in causing changes in the activities of antioxidants, and in the maintenance of photosynthetic activity during the senescence process, and, therefore, on the grain yield of maize under semiarid field conditions. Maize seeds were pretreated with 0 (CK), 200 (PS1), 300 (PS2), and 400 (PS3) mg paclobutrazol L−1. Our results indicated that elevated levels of reactive oxygen species (ROS) and higher accumulation of malondialdehyde (MDA) contents were positively associated with accelerated leaf senescence during the grain-filling periods. The leaf senescence resulted in the disintegration of the photosynthetic pigments and reduced the net photosynthetic rate after silking. However, the resultant ROS burst (O2− and H2O2) was lessened and the leaf senescence and chlorophyll degradation were evidently inhibited in leaves of paclobutrazol-treated maize plants, which was strongly linked with upregulated activities of antioxidant enzymes in treated plants. The enhanced chlorophyll contents and availability of a greater photosynthetic active green leaf area during the grain filling period facilitated the maintenance of higher photosynthetic rate, and light-harvesting efficiency of photosynthesis associated with photosystem II (PSII) resulted in higher kernel number ear−1 and thousand kernel weights, and thus increased the final grain yield. The average maize grain yield was increased by 18.8% to 55.6% in paclobutrazol treatments, compared to untreated control. Among the various paclobutrazol treatments, PS2 (300 mg L−1) treatment showed the most promising effects on enhancing the activities of antioxidative enzymes, delaying leaf senescence and improving the yield of maize. Thus, understanding this effect of paclobutrazol on delaying leaf senescence introduces new possibilities for facilitating yield improvement of maize under semiarid conditions.

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Potential importance of water status traits for durum wheat improvement under Mediterranean conditions

The Journal of Agricultural Science ◽

10.1017/s0021859601001253 ◽

2001 ◽

Vol 137 (2) ◽

pp. 139-145 ◽

Cited By ~ 37

Author(s):

O. MERAH

Keyword(s):

Grain Yield ◽

Durum Wheat ◽

Morphological Traits ◽

Water Status ◽

Flag Leaf ◽

Grain Filling ◽

Dry Matter Partitioning ◽

Growing Seasons ◽

Mediterranean Conditions ◽

Leaf Morphological Traits

Water status traits have been proposed as criteria for drought tolerance improvement in several species especially in bread wheat, oat and barley. In order to test this possibility in durum wheat, in 1995 and 1997, a collection of 144 genotypes from different geographical origins was cultivated under rainfed Mediterranean conditions in Montpellier (southern France). Relative water content (RWC), osmotic potential (OP), as well as leaf morphological traits, grain yield (GY), total above-ground biomass and harvest index (HI) were measured. Large genotypic variations were observed for all traits. Differences between the 2 years were also noticed for all the traits which could be attributed to differences in water availability between the 2 growing seasons. The correlation analysis has revealed significant positive associations between water status traits and both GY and HI within and across years. These results suggest that genotypes which can maintain higher water status and then higher transpiration rates during grain filling, are more efficient in dry matter partitioning to grain and hence higher yield. Heritabilities of water status characters were higher than those of productivity traits. Our results emphasized the value of RWC and OP as criteria for durum wheat grain yield improvement under rainfed Mediterranean conditions. Relationships between RWC, OP and flag leaf morphological traits are also discussed.

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Contrasting response of biomass and grain yield to severe drought in Cappelle Desprez and Plainsman V wheat cultivars

PeerJ ◽

10.7717/peerj.1708 ◽

2016 ◽

Vol 4 ◽

pp. e1708 ◽

Cited By ~ 11

Author(s):

Kenny Paul ◽

János Pauk ◽

Zsuzsanna Deák ◽

László Sass ◽

Imre Vass

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Electron Transport Rate ◽

Biomass Accumulation ◽

Grain Filling ◽

Photosynthetic Parameters ◽

Wheat Cultivars ◽

Flag Leaves ◽

Use Efficiency ◽

Grain Filling Period

We report a case study of natural variations and correlations of some photosynthetic parameters, green biomass and grain yield in Cappelle Desprez and Plainsman V winter wheat (Triticum aestivumL.) cultivars, which are classified as being drought sensitive and tolerant, respectively. We monitored biomass accumulation from secondary leaves in the vegetative phase and grain yield from flag leaves in the grain filling period. Interestingly, we observed higher biomass production, but lower grain yield stability in the sensitive Cappelle cultivar, as compared to the tolerant Plainsman cv. Higher biomass production in the sensitive variety was correlated with enhanced water-use efficiency. Increased cyclic electron flow around PSI was also observed in the Cappelle cv. under drought stress as shown by light intensity dependence of the ratio of maximal quantum yields of Photosystem I and Photosystem II, as well by the plot of the Photosystem I electron transport rate as a function of Photosystem II electron transport rate. Higher CO2uptake rate in flag leaves of the drought-stressed Plainsman cv. during grain filling period correlates well with its higher grain yield and prolonged transpiration rate through spikes. The increase in drought factor (DFI) and performance (PI) indices calculated from variable chlorophyll fluorescence parameters of secondary leaves also showed correlation with higher biomass in the Cappelle cultivar during the biomass accumulation period. However, during the grain filling period, DFI and PI parameters of the flag leaves were higher in the tolerant Plainsman V cultivar and showed correlation with grain yield stability. Our results suggest that overall biomass and grain yield may respond differentially to drought stress in different wheat cultivars and therefore phenotyping for green biomass cannot be used as a general approach to predict grain yield. We also conclude that photosynthetic efficiency of flag and secondary leaves is correlated with grain yield and green biomass, respectively. In addition, secondary trait associated mechanisms like delayed senescence and higher water-use efficiency also contribute to biomass stability. Our studies further prove that photosynthetic parameters could be used to characterize environmental stress responses.

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