scholarly journals 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 ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 187 ◽  
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.

Effect of PASP-KT-NAA on Leaf Senescence and Grain Filling Rate during the Grain-Filling Period in Different Temperature Zones

2013 ◽  
Vol 38 (9) ◽  
pp. 1698-1709
Author(s):  
Tian-Jun XU ◽  
Zhi-Qiang DONG ◽  
Jiao GAO ◽  
Chuan-Xiao CHEN ◽  
Liu JIAO ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Grain Filling ◽  
Filling Rate ◽  
Grain Filling Rate ◽  
Grain Filling Period

scholarly journals Effects of Drought Stress on Some Agronomic and Morpho-Physiological Traits in Durum Wheat Genotypes

2020 ◽  
Vol 12 (14) ◽  
pp. 5610
Author(s):  
Alireza Pour-Aboughadareh ◽  
Reza Mohammadi ◽  
Alireza Etminan ◽  
Lia Shooshtari ◽  
Neda Maleki-Tabrizi ◽  
...  
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Durum Wheat ◽  
Harvest Index ◽  
Plant Biomass ◽  
Geometric Mean ◽  
Grain Filling ◽  
Tolerance Index ◽  
Wheat Genotypes ◽  
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.

Dry matter accumulation and partitioning and its relationship to grain yield in wheat

1995 ◽  
Vol 35 (4) ◽  
pp. 495 ◽  
Author(s):  
RG Flood ◽  
PJ Martin ◽  
WK Gardner
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
The North ◽  
Similar Range ◽  
Total Crop ◽  
Grain Filling Period ◽  
Stem Reserves ◽  
North Western

Total crop dry matter (DM) production and its components, remobilisation of stem reserves, and the relation of these to grain yield were studied in 10 wheat cultivars sown at Walpeup, Boort, and Horsham in the north-western Victorian wheatbelt. Between sites, all DM components decreased in the order Horsham > Boort > Walpeup. Differences between Boort and Walpeup were not always significant. Total DM at anthesis for Walpeu,p and Boort was in a similar range, and less than that for Horsham. Yields increased in the order Walpeup < Boort < Horsham. When data from the 3 sites were combined, leaf, stem (excluding cv. Argentine IX), and total DM were related to grain yield. Within sites, ear DM at anthesis was related to grain yield. Grain yield for all cultivars at Horsham and Walpeup and 5 cultivars at Boort was greater than the increases in crop DM from anthesis to maturity, indicating that pre-anthesis stored assimilates (stem reserves) were used for grain filling. Post-anthesis decrease in stem weight was inversely related to grain yield only at Horsham, which supports the view of utilisation of stem reserves for grain filling at this site. At Boort and Walpeup there was a similar negative trend, but values for 2 cultivars at each site were outliers, which weakened the trend. The wide adaptability of the Australian cultivars used in this study may be related to the differential remobilisation of stem reserves at each site. A measure of yield stability, however, was not related to stem weight loss during the grain-filling period.

scholarly journals Mutation of ONAC096 Enhances Grain Yield by Increasing Panicle Number and Delaying Leaf Senescence during Grain Filling in Rice

2019 ◽  
Vol 20 (20) ◽  
pp. 5241 ◽  
Author(s):  
Kiyoon Kang ◽  
Yejin Shim ◽  
Eunji Gi ◽  
Gynheung An ◽  
Nam-Chon Paek
Keyword(s):  
Grain Yield ◽  
Leaf Senescence ◽  
Grain Filling ◽  
Pcr Analysis ◽  
Cytokinin Oxidase ◽  
Panicle Number ◽  
Reverse Transcription Quantitative Pcr ◽  
Dna Insertion ◽  
Upregulated Genes ◽  
Insertion Mutants

Exploring genetic methods to improve yield in grain crops such as rice (Oryza sativa) is essential to help meet the needs of the increasing population. Here, we report that rice ONAC096 affects grain yield by regulating leaf senescence and panicle number. ONAC096 expression increased rapidly in rice leaves upon the initiation of aging- and dark-induced senescence. Two independent T-DNA insertion mutants (onac096-1 and onac096-2) with downregulated ONAC096 expression retained their green leaf color during natural senescence in the field, thus extending their photosynthetic capacity. Reverse-transcription quantitative PCR analysis showed that ONAC096 upregulated genes controlling chlorophyll degradation and leaf senescence. Repressed OsCKX2 (encoding cytokinin oxidase/dehydrogenase) expression in the onac096 mutants led to a 15% increase in panicle number without affecting grain weight or fertility. ONAC096 mediates abscisic acid (ABA)-induced leaf senescence by upregulating the ABA signaling genes ABA INSENSITIVE5 and ENHANCED EM LEVEL. The onac096 mutants showed a 16% increase in grain yield, highlighting the potential for using this gene to increase grain production.

scholarly journals Barley response to seeding date in central Alberta

2003 ◽  
Vol 83 (2) ◽  
pp. 275-281 ◽  
Author(s):  
P. E. Juskiw ◽  
J. H. Helm
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Seeding Rate ◽  
Hordeum Vulgare L ◽  
Vegetative Period ◽  
Seeding Date ◽  
The Mean ◽  
Grain Filling Period

Seeding date is an important factor influencing productivity of barley (Hordeum vulgare L.). When conditions are conducive to early seeding or result in delayed seeding, producers need to know how cultivars will respond to these seeding situations. In this study, five cultivars (Abee, Harrington, Jackson, Noble and Virden) registered for western Canada were studied for 4 yr (1990 to 1993) when seeded early (late April or early May), in mid-May, in late-May, or late (mid-June) at Lacombe, AB. For all cultivars, early seeding resulted in grain yield advantages of 113 to 134% of the mean site yield, while with late seeding, grain yields were reduced to 54 to 76% of the mean site yield. The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight, and tillers per plant; and increased plant height and percent thins. Late seeding had no significant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Barley responded positively to early seeding in central Alberta, but when seeding was delayed (in this study to mid-June) the early and mid-maturing six-rowed cultivars with short phyllochrons performed better than the two-rowed and late six-rowed cultivars. Key words: Hordeum vulgare L., seeding rate, phenological development, grain quality, grain yield, components

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

2008 ◽  
Vol 110 (3) ◽  
pp. 366-375 ◽  
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

Control of Grain Yield by Sink Capacity and Assimilate Supply in Various Rice (Oryza sativa) cultivars

1991 ◽  
Vol 27 (2) ◽  
pp. 127-135 ◽  
Author(s):  
S. Fukai ◽  
L. Li ◽  
P. T. Vizmonte ◽  
K. S. Fischer
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Grain Filling ◽  
Grain Weight ◽  
Rice Cultivars ◽  
Sink Capacity ◽  
Single Grain ◽  
Grain Filling Period

SummaryThe objective of this study was to identify whether grain yield in four contrasting rice cultivars is limited by supply of assimilate to fill the grains or by sink capacity to accept the assimilate. Grain yield was limited mostly by sink capacity, with little variation in single grain weight among cultivars, but an old cultivar showed some ability to adjust single grain weight. Sink capacity was very sensitive to variation in assimilate supply immediately after anthesis. Reduction in assimilate supply in the anthesis to early grain filling period reduced filled grain percentage and grain yield, particularly in high yielding cultivars with a large number of grains per panicle.

Heat stress in grain legumes during reproductive and grain-filling phases

2017 ◽  
Vol 68 (11) ◽  
pp. 985 ◽  
Author(s):  
Muhammad Farooq ◽  
Faisal Nadeem ◽  
Nirmali Gogoi ◽  
Aman Ullah ◽  
Salem S. Alghamdi ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Leaf Senescence ◽  
Management Strategies ◽  
Substantial Reduction ◽  
Grain Filling ◽  
Grain Legumes ◽  
Grain Legume ◽  
The Impact

Thermal stress during reproductive development and grain-filling phases is a serious threat to the quality and productivity of grain legumes. The optimum temperature range for grain legume crops is 10−36°C, above which severe losses in grain yield can occur. Various climatic models have simulated that the temperature near the earth’s surface will increase (by up to 4°C) by the end of this century, which will intensify the chances of heat stress in crop plants. The magnitude of damage or injury posed by a high-temperature stress mainly depends on the defence response of the crop and the specific growth stage of the crop at the time of exposure to the high temperature. Heat stress affects grain development in grain legumes because it disintegrates the tapetum layer, which reduces nutrient supply to microspores leading to premature anther dehiscence; hampers the synthesis and distribution of carbohydrates to grain, curtailing the grain-filling duration leading to low grain weight; induces poor pod development and fractured embryos; all of which ultimately reduce grain yield. The most prominent effects of heat stress include a substantial reduction in net photosynthetic rate, disintegration of photosynthetic apparatus and increased leaf senescence. To curb the catastrophic effect of heat stress, it is important to improve heat tolerance in grain legumes through improved breeding and genetic engineering tools and crop management strategies. In this review, we discuss the impact of heat stress on leaf senescence, photosynthetic machinery, assimilate translocation, water relations, grain quality and development processes. Furthermore, innovative breeding, genetic, molecular and management strategies are discussed to improve the tolerance against heat stress in grain legumes.

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

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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