Spikelet fertility and heat shock transcription factor (Hsf) gene responses to heat stress in tolerant and susceptible rice (Oryza sativa L.) genotypes

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.

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Assessment of Morphometric Diversity for Yield and Yield Attributing Traits in Rice (Oryza sativa L.) for Tolerance to Heat Stress

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2020/v39i1030626 ◽

2020 ◽

pp. 29-49

Author(s):

S. Sandeep ◽

M. Sujatha ◽

L. V. Subbarao ◽

C. N. Neeraja

Keyword(s):

Principal Component Analysis ◽

Oryza Sativa ◽

Heat Stress ◽

Oryza Sativa L ◽

Pollen Viability ◽

Principal Component ◽

Component Analysis ◽

Spikelet Fertility ◽

Breeding Programmes ◽

Heat Tolerant

The present investigation entitled “Assessment of morphometric diversity for yield and yield attributing traits in rice (Oryza sativa L.) for tolerance to heat stress” was carried out with objective of assessing genetic divergence in 200 germplasm of rice for eleven characters at ICRISAT, Patencheru, Hyderabad. The genotypes were grouped into fifteen clusters in Tocher’s method, cluster analysis and principal component analysis, out of the 11 characters studied, number of grains per panicle, plant height, pollen viability and spikelet fertility contributed 96.73 per cent of the total divergence and these traits were found to be important potent factors for genetic differentiation in genotypes. Principal component analysis identified five principal components, which contributed for 78.66 percent % of cumulative variance. The overall results of the study revealed that crossing using the genotypes under cluster V and XI and cluster XI and XIII could be exploited by hybridization programme to yield good recombinants because they had maximum inter cluster distance and possessing high genetic diversity for the characters viz. panicle length, number of grains per panicle and single plant yield. The genotypes of cluster I, II, IV, VI, VII, VIII, XI, XII and XIII showed high spikelet fertility percentage. Hence the genotypes of these clusters can be used in breeding programmes for development of heat tolerant varieties. Euclidean2 method indicated that genotypes of cluster III and IX exhibited high spikelet fertility percentage which can be utilized in development of heat tolerant cultivars. The results of principal component analysis revealed that genotypes of cluster I, cluster IV, cluster V, cluster VIII, cluster IX, cluster XI, cluster XII and cluster XV exhibited highest spikelet fertility percentage. Hence, the genotypes of the clusters can be used in breeding programmes for the development of heat tolerant varieties.

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A phenotypic marker for quantifying heat stress impact during microsporogenesis in rice (Oryza sativa L.)

Functional Plant Biology ◽

10.1071/fp13086 ◽

2014 ◽

Vol 41 (1) ◽

pp. 48 ◽

Cited By ~ 34

Author(s):

Krishna S. V. Jagadish ◽

Peter Craufurd ◽

Wanju Shi ◽

Rowena Oane

Keyword(s):

Oryza Sativa ◽

Heat Stress ◽

Oryza Sativa L ◽

Flag Leaf ◽

Environmental Stability ◽

Spikelet Sterility ◽

Phenotypic Marker ◽

Male Gametogenesis ◽

The Right ◽

The Impact

Gametogenesis in rice (Oryza sativa L.), and particularly male gametogenesis, is a critical developmental stage affected by different abiotic stresses. Research on this stage is limited, as flowering stage has been the major focus for research to date. Our main objective was to identify a phenotypic marker for male gametogenesis and the duration of exposure needed to quantify the impact of heat stress at this stage. Spikelet size coinciding with microsporogenesis was identified using parafilm sectioning, and the panicle (spikelet) growth rate was established. The environmental stability of the marker was ascertained with different nitrogen (75 and 125 kg ha–1) and night temperature (22°C and 28°C) combinations under field conditions. A distance of –8 to –9 cm between the collar of the last fully opened leaf and the flag leaf collar, which was yet to emerge was identified as the environmentally stable phenotypic marker. Heat stress (38°C) imposed using the identified marker induced 8–63% spikelet sterility across seven genetically diverse rice genotypes. Identifying the right stage based on the marker information and imposing 6 consecutive days of heat stress ensures that >95% of the spikelets in a panicle are stressed spanning across the entire microsporogenesis stage.

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Effect of high temperature on the reproductive development of chickpea genotypes under controlled environments

Functional Plant Biology ◽

10.1071/fp12033 ◽

2012 ◽

Vol 39 (12) ◽

pp. 1009 ◽

Cited By ~ 72

Author(s):

Viola Devasirvatham ◽

Pooran M. Gaur ◽

Nalini Mallikarjuna ◽

Raju N. Tokachichu ◽

Richard M. Trethowan ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Pollen Germination ◽

Pollen Viability ◽

Pollen Grains ◽

High Temperature Stress ◽

Pollen Production ◽

Seed Number ◽

Controlled Environments

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.

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Mapping segregation distortion loci and quantitative trait loci for spikelet sterility in rice (Oryza sativa L.)

Genetics Research ◽

10.1017/s0016672305007779 ◽

2005 ◽

Vol 86 (2) ◽

pp. 97-106 ◽

Cited By ~ 83

Author(s):

CHUNMING WANG ◽

CHENGSONG ZHU ◽

HUQU ZHAI ◽

JIANMIN WAN

Keyword(s):

Oryza Sativa ◽

Segregation Distortion ◽

Quantitative Trait ◽

Oryza Sativa L ◽

Segregation Ratio ◽

Chromosome 8 ◽

Spikelet Fertility ◽

Spikelet Sterility ◽

Multipoint Method ◽

Two Populations

Markers with segregation ratio distortion are commonly observed in data sets used for quantitative trait locus (QTL) mapping. In this study, a multipoint method of maximum likelihood (ML) was newly developed to estimate the positions and effects of the segregation distortion loci (SDLs) in two F2 populations of rice (Oryza sativa L.), i.e. Taichung65/Bhadua (TB; japonica–indica cross) and CPSLO17/W207-2 (CW; japonica–japonica). Of the four parents, W207-2 and Bhadua were found to be spikelet semi-sterile and stably inherited through selfing, and spikelet fertility segregated in the two populations. Therefore, recombination frequencies were recalculated after mapping the SDLs by using the multipoint method, and the molecular linkage maps of the two F2 populations were constructed to detect QTLs underlying spikelet fertility. As a result, five SDLs in the TB population were mapped on chromosomes 1, 3, 8 and 9, respectively. Two major QTLs underlying spikelet fertility, namely qSS-6a and qSS-8a, were detected on chromosomes 6 and 8, respectively. In the CW population, a total of 12 SDLs were detected on all 12 chromosomes except 1, 5, 7 and 11. Three QTLs underlying spikelet sterility, namely qSS-2, qSS-6b and qSS-8b on chromosomes 2, 6 and 8, were determined on the whole genome scale. Interestingly, both qSS-6a and qSS-6b, detected in the two F2 populations respectively, were located on a similar position as the S5 gene on chromosome 6; while qSS-8a and qSS-8b were also simultaneously detected on similar positions of the short arm of chromosome 8 in the two populations, which should be a new sterility gene showing the same type of zygotic selection.

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Quantifying the Impact of Heat Stress on Pollen Germination, Seed Set, and Grain Filling in Spring Wheat

Crop Science ◽

10.2135/cropsci2018.05.0292 ◽

2019 ◽

Vol 59 (2) ◽

pp. 684-696 ◽

Cited By ~ 10

Author(s):

Raju Bheemanahalli ◽

V. S. John Sunoj ◽

Gautam Saripalli ◽

P. V. Vara Prasad ◽

H. S. Balyan ◽

...

Keyword(s):

Heat Stress ◽

Spring Wheat ◽

Pollen Germination ◽

Seed Set ◽

Grain Filling ◽

The Impact

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Study of anther dehiscence, pollen viability and stigma receptivity in rice (Oryza sativa L.)

International Journal of Chemical Studies ◽

10.22271/chemi.2020.v8.i3am.9616 ◽

2020 ◽

Vol 8 (3) ◽

pp. 2677-2680

Author(s):

BS Thorat ◽

RL Kunkerkar ◽

SR Kadam ◽

SG Bhave ◽

JP Devmore

Keyword(s):

Oryza Sativa ◽

Oryza Sativa L ◽

Pollen Viability ◽

Anther Dehiscence ◽

Stigma Receptivity

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Abnormal Anther Development Leads to Lower Spikelet Fertility in Rice (Oryza Sativa L.) Under High Temperature During the Panicle Initiation Stage

10.21203/rs.3.rs-104822/v1 ◽

2020 ◽

Author(s):

Qiuqian Hu ◽

Kehui Cui ◽

Wencheng Wang ◽

Qifan Lu ◽

Jianliang Huang ◽

...

Keyword(s):

Oryza Sativa ◽

High Temperature ◽

Grain Yield ◽

Heat Tolerance ◽

Pollen Viability ◽

Anther Development ◽

Spikelet Fertility ◽

Anther Wall ◽

Anther Dehiscence ◽

Initiation Stage

Abstract Background: Decreased spikelet fertility is often responsible for reduction in grain yield in rice (Oryza sativa L.). In this study, two varieties with different levels of heat tolerance, Liangyoupeijiu (LYPJ, heat susceptible) and Shanyou63 (SY63, heat tolerant) were subjected to two temperature treatments for 28 days during the panicle initiation stage in temperature/relative humidity-controlled greenhouses: high temperature (HT; 37/27℃; day/night) and control temperature (CK; 31/27℃; day/night) to investigate changes in anther development under HT during panicle initiation and their relationship with spikelet fertility.Results: HT significantly decreased the grain yield of LYPJ by decreasing the number of spikelets per panicle and seed setting percentage. In addition, HT produced minor adverse effects in SY63. The decreased spikelet fertility was primarily attributed to decreased pollen viability and anther dehiscence, as well as poor pollen shedding of the anthers of LYPJ under HT. HT resulted in abnormal anther development (fewer vacuolated microspores, un-degraded tapetum, unevenly distributed Ubisch bodies) and malformation of pollen (obscure outline of the pollen exine with a collapsed bacula, disordered tectum, and no nexine of the pollen walls, uneven sporopollenin deposition on the surface of pollen grains) in LYPJ, which may have lowered pollen viability. Additionally, HT produced a compact knitted anther cuticle structure of the epidermis, an un-degraded septum, a thickened anther wall, unevenly distributed Ubisch bodies, and inhibition of the confluent locule, and these malformed structures may be partially responsible for the decreased anther dehiscence rate and reduced pollen shedding of the anthers in LYPJ. In contrast, the anther wall and pollen development of SY63 were not substantially changed under HT. Conclusions: Our results suggest that disturbed anther walls and pollen development are responsible for the reduced spikelet fertility and grain yield of the tested heat susceptible variety, and noninvasive anthers and pollen formation in response to HT were associated with improved heat tolerance.

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Performance of Some Rice (Oryza sativa L.) Cultivars under Water Shortage and High Temperature Stress

Sains Malaysiana ◽

10.17576/jsm-2021-5003-05 ◽

2021 ◽

Vol 50 (3) ◽

pp. 617-628

Author(s):

MOHAMED A.A.E. ◽

SAJID FIAZ ◽

XIUKANG WANG ◽

MOHSIN ALI ◽

NOSHI PARVEEN ◽

...

Keyword(s):

Heat Stress ◽

Abiotic Stresses ◽

Oryza Sativa L ◽

Flag Leaf ◽

Crop Improvement ◽

Water Shortage ◽

High Temperature Stress ◽

Yield Potential ◽

High Yield ◽

Leaf Angle

Water shortage and heat are the most devastating abiotic stresses threating global food security. To understand the behavior of germplasm under both abiotic stresses, thirteen rice genotypes were selected for the study to make evaluation under water shortage and heat stress condition. The results showed that the year mean squares were significant and highly significant for all agronomical traits except, flag leaf area, number of tillers plant-1, number of panicles plant-1, 100 grain weight, grain yield plant-1 and harvest index indicated overall wide differences of weather during both years. Environments mean squares were found to be highly significant over all traits were used, indicating that all environments showed significant differences. The highly significant differences were observed among genotypes and G x E interaction for all characteristics except, panicle length. Concerning the cultivars performance across three environments, the cultivars Giza 178, Giza 179, Sakha 107, Hybrid 1, Hybrid 2 gave the best desirable values over normal, drought and heat stress conditions so, these cultivars are considered to play vital role in breeding program to enhancement for drought and heat stresses and have high yield potential. The highly significant and positive correlation were found among the all traits under investigation except with flag leaf angle, leaf rolling and sterility percentage. The results will further help to utilize the genotypes for further crop improvement breeding programs.

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Abnormal anther development leads to lower spikelet fertility in rice (Oryza sativa L.) under high temperature during the panicle initiation stage

BMC Plant Biology ◽

10.1186/s12870-021-03209-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Qiuqian Hu ◽

Wencheng Wang ◽

Qifan Lu ◽

Jianliang Huang ◽

Shaobing Peng ◽

...

Keyword(s):

Oryza Sativa ◽

High Temperature ◽

Grain Yield ◽

Heat Tolerance ◽

Pollen Viability ◽

Anther Development ◽

Spikelet Fertility ◽

Anther Wall ◽

Anther Dehiscence ◽

Initiation Stage

Abstract Background Decreased spikelet fertility is often responsible for reduction in grain yield in rice (Oryza sativa L.). In this study, two varieties with different levels of heat tolerance, Liangyoupeijiu (LYPJ, heat susceptible) and Shanyou63 (SY63, heat tolerant) were subjected to two temperature treatments for 28 days during the panicle initiation stage in temperature/relative humidity-controlled greenhouses: high temperature (HT; 37/27 °C; day/night) and control temperature (CK; 31/27 °C; day/night) to investigate changes in anther development under HT during panicle initiation and their relationship with spikelet fertility. Results HT significantly decreased the grain yield of LYPJ by decreasing the number of spikelets per panicle and seed setting percentage. In addition, HT produced minor adverse effects in SY63. The decreased spikelet fertility was primarily attributed to decreased pollen viability and anther dehiscence, as well as poor pollen shedding of the anthers of LYPJ under HT. HT resulted in abnormal anther development (fewer vacuolated microspores, un-degraded tapetum, unevenly distributed Ubisch bodies) and malformation of pollen (obscure outline of the pollen exine with a collapsed bacula, disordered tectum, and no nexine of the pollen walls, uneven sporopollenin deposition on the surface of pollen grains) in LYPJ, which may have lowered pollen viability. Additionally, HT produced a compact knitted anther cuticle structure of the epidermis, an un-degraded septum, a thickened anther wall, unevenly distributed Ubisch bodies, and inhibition of the confluent locule, and these malformed structures may be partially responsible for the decreased anther dehiscence rate and reduced pollen shedding of the anthers in LYPJ. In contrast, the anther wall and pollen development of SY63 were not substantially changed under HT. Conclusions Our results suggest that disturbed anther walls and pollen development are responsible for the reduced spikelet fertility and grain yield of the tested heat susceptible variety, and noninvasive anthers and pollen formation in response to HT were associated with improved heat tolerance.

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