Mapping QTLs for yield components and chlorophyll a fluorescence parameters in wheat under three levels of water availability

Drought is one of the major factors limiting wheat yield in many developing countries worldwide. Parameters of chlorophyll a fluorescence kinetics under drought stress conditions have been used to characterize dehydration tolerance in wheat. In the present study, a set of 94 doubled haploid lines obtained from Chinese Spring × SQ1 (CSDH), mapped with 450 markers, was evaluated for yield (grain dry weight/main stem ear), number of grains/main stem ear (NG) and chlorophyll a fluorescence parameters (FC) under moderate and severe drought stress, and compared with results for well-watered plants. quantitative trait loci (QTLs) were identified using Windows QTLCartographer version 2.5 software and the results were analysed using single-marker analysis (SMA) and composite interval mapping (CIM). Analysis using SMA and CIM showed mostly similar QTLs for all traits, though more QTLs were identified by SMA than by CIM. The genetic control of yield, NG and FC varied considerably between drought-stressed and non-stressed plants. Although no major QTL co-locations were found for yield and FC using CIM, the co-location of QTLs for NG, yield and Fv/Fm in drought-stressed plants was observed on chromosome 5A using SMA.

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Study some of Morphological and Physiological Traits of Kurrajong Brachychiton populneus (Schott & Endl.) Seedlings Planted under Water Stress Conditions

Basrah Journal of Agricultural Sciences ◽

10.37077/25200860.2020.33.1.16 ◽

2020 ◽

Vol 33 (1) ◽

pp. 213-220

Author(s):

Shaima A. Karim ◽

Sirwa A. Qadir ◽

Halmat A. Sabr

Keyword(s):

Drought Stress ◽

Water Content ◽

Chlorophyll A ◽

Relative Water Content ◽

Photosynthetic Pigment ◽

Total Content ◽

Dry Weight ◽

Severe Drought ◽

Shoot Height ◽

Relative Water

In this study, Brachychiton populneus seedlings were subjected to drought stress for 90 Days and physiological and morphological characters analyzed to determine their response to water deficit. The growth characters including, height and diameter of shoots, the dry weight of shoots and roots as well as photosynthetic pigment and the leaves content of relative water content were measured to evaluate the effects of drought in the physiological growth of plant. The lowest means; 59 cm and 8 mm of shoot height and diameter respectively were recorded at 30% of water holding capacity of soil (WHC). Drought treated seedlings at both 60% and 30% WHC had lower dry weight of shoots; 9.54 and 8.24 g plant-1 respectively compared to the control. Consequently, the increase of drought conditions led to enhancement the growth of roots and roots to shoots ratio. The highest increase in the dry weight of roots and roots to shoots ratio were25.96 g plant-1 and 3.19 recorded under severe drought stress condition. Lowest amount of chlorophyll a; 2.94 mg g-1 F W recorded under 30% SWHC. It is found also the total content of chlorophyll in the leaves decreased significantly; 5.86 and 7.88 mg g-1 F W under both levels. While the highest ratio of chlorophyll a: b was 1.59 recorded at 60% SWHC. However, the lowest leave relative water content LRWC%; 86% was recorded under 30% SWHC. These findings may explain the characters of the early growth and physiological responses of, Brachychiton populneus to dehydration and facilitate the selection of drought-resistant tree families.

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Role of Suillus placidus in Improving the Drought Tolerance of Masson Pine (Pinus massoniana Lamb.) Seedlings

Forests ◽

10.3390/f12030332 ◽

2021 ◽

Vol 12 (3) ◽

pp. 332

Author(s):

Min Li ◽

Haoyun Wang ◽

Xizhou Zhao ◽

Zhongke Lu ◽

Xueguang Sun ◽

...

Keyword(s):

Drought Stress ◽

Defense Mechanism ◽

Southern China ◽

Dry Weight ◽

Pinus Massoniana ◽

Photosynthetic Performance ◽

Ectomycorrhizal Fungus ◽

Severe Drought ◽

Masson Pine ◽

Pine Seedlings

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.

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Linking changes in chlorophyll a fluorescence with drought stress susceptibility in mung bean [ Vigna radiata (L.) Wilczek]

Physiologia Plantarum ◽

10.1111/ppl.13327 ◽

2021 ◽

Author(s):

Hussan Bano ◽

Habib‐ur‐Rehman Athar ◽

Zafar Ullah Zafar ◽

Hazem M. Kalaji ◽

Muhammad Ashraf

Keyword(s):

Drought Stress ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Vigna Radiata ◽

Mung Bean ◽

Stress Susceptibility

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Over-Optimistic Projected Future Wheat Yield Potential in the North China Plain: The Role of Future Climate Extremes

Agronomy ◽

10.3390/agronomy12010145 ◽

2022 ◽

Vol 12 (1) ◽

pp. 145

Author(s):

Rui Yang ◽

Panhong Dai ◽

Bin Wang ◽

Tao Jin ◽

Ke Liu ◽

...

Keyword(s):

Drought Stress ◽

North China Plain ◽

North China ◽

Crop Yields ◽

Wheat Yield ◽

Yield Potential ◽

Severe Drought ◽

The North ◽

The North China Plain ◽

Stress Environments

Global warming and altered precipitation patterns pose a serious threat to crop production in the North China Plain (NCP). Quantifying the frequency of adverse climate events (e.g., frost, heat and drought) under future climates and assessing how those climatic extreme events would affect yield are important to effectively inform and make science-based adaptation options for agriculture in a changing climate. In this study, we evaluated the effects of heat and frost stress during sensitive phenological stages at four representative sites in the NCP using the APSIM-wheat model. climate data included historical and future climates, the latter being informed by projections from 22 Global Climate Models (GCMs) in the Coupled Model Inter-comparison Project phase 6 (CMIP6) for the period 2031–2060 (2050s). Our results show that current projections of future wheat yield potential in the North China Plain may be overestimated; after more accurately accounting for the effects of frost and heat stress in the model, yield projections for 2031-60 decreased from 31% to 9%. Clustering of common drought-stress seasonal patterns into key groups revealed that moderate drought stress environments are likely to be alleviated in the future, although the frequency of severe drought-stress environments would remain similar (25%) to that occurring under the current climate. We highlight the importance of mechanistically accounting for temperature stress on crop physiology, enabling more robust projections of crop yields under future the burgeoning climate crisis.

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Seasonality and Small Spatial-Scale Variation of Chlorophyll a Fluorescence in Bryophyte Syntrichia ruralis [Hedw.] in Semi-Arid Sandy Grassland, Hungary

Plants ◽

10.3390/plants9010092 ◽

2020 ◽

Vol 9 (1) ◽

pp. 92 ◽

Cited By ~ 1

Author(s):

Ruchika ◽

Zsolt Csintalan ◽

Evelin Ramóna Péli

Keyword(s):

Quantum Yield ◽

Fluorescence Quenching ◽

Spatial Scale ◽

Chlorophyll A ◽

Chlorophyll A Fluorescence ◽

Small Spatial Scale ◽

Variation Trend ◽

Fluorescence Parameters ◽

Semi Arid ◽

Sandy Grassland

Bryophytes face challenges due to global climate change which is leading to in-depth research in monitoring and studying their photosynthetic activity. The aim of this preliminary experiment was to study the seasonal variation trend in the chlorophyll a fluorescence parameters, Fv/Fm (ratio of variable to maximum fluorescence), photochemical fluorescence quenching (qP), photochemical quantum yield of photosystem II (ΦPS II), fluorescence quenching (qN), and non-photochemical quenching (NPQ), in the moss cushions of Syntrichia ruralis [Hedw.] collected from semi-arid sandy dunes for two slopes i.e., north-east (NE) and south-west (SW) direction. Our results showed a seasonal and small-spatial scale variation trend in all chlorophyll fluorescence parameters. These variations are due to different seasonal conditions referring to different degrees of environmental stress. ΦPS II and qP values were maximum in winter and in spring seasons while Fv/Fm, NPQ and qN were maximum in summer. Based on the different exposition of dunes, the SW slope showed increased values of the effective quantum yield of PS II and qP in comparison to the NE slope due to the optimal microclimate conditions for their expansion. These results may refer to the future changing in diversification and coverage of the Syntrichia species in semi-arid sandy grassland due to more effective metabolism in the beneficial microclimatic conditions.

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