Responses of Thai recommended rice cultivars to high temperature in PSII efficiency at panicle initiation stage

SummaryExperiments were conducted in glasshouses at IRRI, Philippines, during 1987 and 1988 to identify varietal differences in apical development using six rice cultivars having extreme characters; Jirasar 280 (early senescence), Neo-Dunghan 1 (late senescence), Macunting (small seeds), ABB (large seeds), C12474–1 (long culm), and B581–A6–458 (short culm); and five cultivars, IR20, IR22, IR34, IR54, IR64, of the same growth duration.The length of time from physiological panicle initiation (PI) to flowering varied from 25 to 50 days. The onset of physiological PI occurred when the fourth penultimate leaf was fully exserted. The visual panicle initiation stage (VPI) coincided with spikelet differentiation in all cultivars. Nitrogen top-dressing at 55–57 days before the anticipated maturity date (the present N management recommendation) did not coincide with the actual panicle initiation stage in any of the cultivars and the major yield determinants (i.e. the primary and secondary branches) therefore differentiated in conditions of internal nitrogen shortage. Spikelet abortion took place both before and after flowering. Reduction of pre-flowering abortion is important in increasing rice grain yields and could be achieved by improved N management. It is important to recognise cultivar differences and periods of loss of potential yield in developing efficient N management protocols.

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Changes in NMR Relaxation of Rice Grains, Kernel Quality and Physicochemical Properties in Response to a High Temperature after Flowering in Heat-Tolerant and Heat-Sensitive Rice Cultivars

Plant Production Science ◽

10.1626/pps.12.185 ◽

2009 ◽

Vol 12 (2) ◽

pp. 185-192 ◽

Cited By ~ 17

Author(s):

Kohei Tanaka ◽

Ryoki Onishi ◽

Masayuki Miyazaki ◽

Yushi Ishibashi ◽

Takashi Yuasa ◽

...

Keyword(s):

High Temperature ◽

Physicochemical Properties ◽

Nmr Relaxation ◽

Rice Cultivars ◽

Rice Grains ◽

Kernel Quality ◽

Heat Tolerant

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Effect of High Temperature Intermittent Drying on Rice Seed Viability and Vigor

International Journal of Food Engineering ◽

10.1515/ijfe-2016-0433 ◽

2017 ◽

Vol 13 (10) ◽

Author(s):

Pan Wang ◽

Dong Li ◽

Li-jun Wang ◽

Benu Adhikari

Keyword(s):

High Temperature ◽

Ambient Temperature ◽

Seed Viability ◽

Seed Vigor ◽

Drying Rate ◽

Rice Seed ◽

Rice Cultivars ◽

Moisture Contents ◽

Rice Seeds ◽

Tempering Process

AbstractThis work aimed at determining whether high temperature intermittent drying followed by tempering at ambient temperature could preserve the seed viability and vigor.JaponicaandIndicarice seeds with 21.2 % and 22.6 % wet moisture contents (w.b.) were dried at 50 ºC and 60ºC for either 5, 10, 15 or 20 minutes, followed by tempering at 25ºC for 45 minutes. Each drying cycle was repeated until the rice seeds were dried to 12.0 % (w.b.). The drying rate was improved and the total in-dryer time was reduced in the intermittent drying when compared to continuous drying, due to the tempering process. The seed vigor was significantly reduced by intermittent drying at 60 °C with all exposure times, although the seed still kept the ability to germinate for both rice cultivars. The intermittent drying at 50 ºC for 5 minutes per drying cycle preserved the seed vigor ofJaponicarice well, while inIndicarice, the intermittent drying at 50 ºC up to 20 minutes could still be able to maintain the seed vigor.

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Starch Morphology and Metabolomic Analyses Reveal That the Effect of High Temperature on Cooked Rice Elongation and Expansion Varied in Indica and Japonica Rice Cultivars

Agronomy ◽

10.3390/agronomy11122416 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2416

Author(s):

Nnaemeka Emmanuel Okpala ◽

Mouloumdema Pouwedeou Potcho ◽

Muhammad Imran ◽

Tianyue An ◽

Gegen Bao ◽

...

Keyword(s):

High Temperature ◽

Low Temperature ◽

Oryza Sativa L ◽

Effect Of Temperature ◽

Japonica Rice ◽

Rice Cultivars ◽

Starch Granules ◽

Cooked Rice ◽

Temperature Regimes ◽

Badh2 Gene

Rice (Oryza sativa L.) is mainly grouped into indica and japonica varieties. The aim of this study was to investigate the effect of temperature on cooked rice elongation, cooked rice expansion, and rice fragrance. This study was conducted in three growth temperature chambers with indica cultivar Basmati 385 (B385) and japonica cultivar Yunjingyou (YJY). Grains of B385 grown in low-temperature regimes had the highest cooked rice elongation and expansion, whereas the grains of YJY grown in high-temperature regimes had the highest cooked rice elongation and expansion. Starch granules of B385 grown in low-temperature regimes were more compact and bigger, compared to grains grown in medium- and high-temperature regimes. Conversely, the starch granules of YJY grown in high-temperature regimes were more compact and bigger, compared to those grown in medium- and low-temperature regimes. Metabolomic analyses showed that temperature affected the rice metabolome and revealed that cyclohexanol could be responsible for the differences observed in cooked rice elongation and expansion percentage. However, in both B385 and YJY, grains from low-temperature regimes had the highest 2-AP content and the lowest expression levels of the badh2 gene. The findings of this study will be useful to rice breeders and producers.

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Effect of High Temperature at Ripening Stage on the Reserve Accumulation in Seed in Some Rice Cultivars

Plant Production Science ◽

10.1626/pps.5.160 ◽

2002 ◽

Vol 5 (2) ◽

pp. 160-168 ◽

Cited By ~ 86

Author(s):

Sabaruddin Zakaria ◽

Toshiaki Matsuda ◽

Shingo Tajima ◽

Youji Nitta

Keyword(s):

High Temperature ◽

Rice Cultivars ◽

Ripening Stage ◽

Reserve Accumulation

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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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