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Impact of high temperature stress on floret fertility and individual grain weight of grain sorghum: sensitive stages and thresholds for temperature and duration.

Prasad PV, Djanaguiraman M, Perumal R, Ciampitti IA - Front Plant Sci (2015)

Bottom Line: Sorghum [Sorghum bicolor (L.) Moench] yield formation is severely affected by high temperature stress during reproductive stages.Temperatures ranging from 25 to 37°C quadratically decreased individual grain weight when imposed at the start of grain filling.In field conditions, imposition of temperature stress (using heat tents) during floret development or grain filling stage also decreased floret fertility, individual grain weight, and grain weight per panicle.

View Article: PubMed Central - PubMed

Affiliation: Department of Agronomy, Throckmorton Plant Science Center, Kansas State University Manhattan, KS, USA.

ABSTRACT
Sorghum [Sorghum bicolor (L.) Moench] yield formation is severely affected by high temperature stress during reproductive stages. This study pursues to (i) identify the growth stage(s) most sensitive to high temperature stress during reproductive development, (ii) determine threshold temperature and duration of high temperature stress that decreases floret fertility and individual grain weight, and (iii) quantify impact of high daytime temperature during floret development, flowering and grain filling on reproductive traits and grain yield under field conditions. Periods between 10 and 5 d before anthesis; and between 5 d before- and 5 d after-anthesis were most sensitive to high temperatures causing maximum decreases in floret fertility. Mean daily temperatures >25°C quadratically decreased floret fertility (reaching 0% at 37°C) when imposed at the start of panicle emergence. Temperatures ranging from 25 to 37°C quadratically decreased individual grain weight when imposed at the start of grain filling. Both floret fertility and individual grain weights decreased quadratically with increasing duration (0-35 d or 49 d during floret development or grain filling stage, respectively) of high temperature stress. In field conditions, imposition of temperature stress (using heat tents) during floret development or grain filling stage also decreased floret fertility, individual grain weight, and grain weight per panicle.

No MeSH data available.


Related in: MedlinePlus

Impact of high temperature stress imposed by heat tents (40/16°C, daytime maximum/nighttime minimum) relative outside heat tent ambient conditions (30/15°C, daytime maximum/nighttime minimum) from start of grain filling to harvest maturity on (A) number of florets per panicle, (B) number of seeds per panicle, (C) floret fertility (%), (D) individual grain weight (mg), and (E) grain weight per panicle (g). Each datum is shown with ± SE. Numbers on top of the bars shows the percentage decline under high temperature stress conditions (inside heat tents) from outside ambient conditions.
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Figure 9: Impact of high temperature stress imposed by heat tents (40/16°C, daytime maximum/nighttime minimum) relative outside heat tent ambient conditions (30/15°C, daytime maximum/nighttime minimum) from start of grain filling to harvest maturity on (A) number of florets per panicle, (B) number of seeds per panicle, (C) floret fertility (%), (D) individual grain weight (mg), and (E) grain weight per panicle (g). Each datum is shown with ± SE. Numbers on top of the bars shows the percentage decline under high temperature stress conditions (inside heat tents) from outside ambient conditions.

Mentions: Similarly, in the experiment where high temperature stress was imposed during grain filling, daytime hourly mean maximum temperature outside the heat tent (ambient) was 30°C, while inside heat tent (high temperature) was 40°C (Figure 8A). However, the nighttime hourly mean minimum temperature outside (ambient) and inside heat tent were comparable (15–16°C) (Figure 8B). The daytime high temperature stress did not cause any difference in the number of florets per panicle, seeds per panicle or floret fertility, but significantly decreased individual grain weight by 15% and grain weight per panicle by 20% as compared with outside ambient temperatures (Figure 9).


Impact of high temperature stress on floret fertility and individual grain weight of grain sorghum: sensitive stages and thresholds for temperature and duration.

Prasad PV, Djanaguiraman M, Perumal R, Ciampitti IA - Front Plant Sci (2015)

Impact of high temperature stress imposed by heat tents (40/16°C, daytime maximum/nighttime minimum) relative outside heat tent ambient conditions (30/15°C, daytime maximum/nighttime minimum) from start of grain filling to harvest maturity on (A) number of florets per panicle, (B) number of seeds per panicle, (C) floret fertility (%), (D) individual grain weight (mg), and (E) grain weight per panicle (g). Each datum is shown with ± SE. Numbers on top of the bars shows the percentage decline under high temperature stress conditions (inside heat tents) from outside ambient conditions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594118&req=5

Figure 9: Impact of high temperature stress imposed by heat tents (40/16°C, daytime maximum/nighttime minimum) relative outside heat tent ambient conditions (30/15°C, daytime maximum/nighttime minimum) from start of grain filling to harvest maturity on (A) number of florets per panicle, (B) number of seeds per panicle, (C) floret fertility (%), (D) individual grain weight (mg), and (E) grain weight per panicle (g). Each datum is shown with ± SE. Numbers on top of the bars shows the percentage decline under high temperature stress conditions (inside heat tents) from outside ambient conditions.
Mentions: Similarly, in the experiment where high temperature stress was imposed during grain filling, daytime hourly mean maximum temperature outside the heat tent (ambient) was 30°C, while inside heat tent (high temperature) was 40°C (Figure 8A). However, the nighttime hourly mean minimum temperature outside (ambient) and inside heat tent were comparable (15–16°C) (Figure 8B). The daytime high temperature stress did not cause any difference in the number of florets per panicle, seeds per panicle or floret fertility, but significantly decreased individual grain weight by 15% and grain weight per panicle by 20% as compared with outside ambient temperatures (Figure 9).

Bottom Line: Sorghum [Sorghum bicolor (L.) Moench] yield formation is severely affected by high temperature stress during reproductive stages.Temperatures ranging from 25 to 37°C quadratically decreased individual grain weight when imposed at the start of grain filling.In field conditions, imposition of temperature stress (using heat tents) during floret development or grain filling stage also decreased floret fertility, individual grain weight, and grain weight per panicle.

View Article: PubMed Central - PubMed

Affiliation: Department of Agronomy, Throckmorton Plant Science Center, Kansas State University Manhattan, KS, USA.

ABSTRACT
Sorghum [Sorghum bicolor (L.) Moench] yield formation is severely affected by high temperature stress during reproductive stages. This study pursues to (i) identify the growth stage(s) most sensitive to high temperature stress during reproductive development, (ii) determine threshold temperature and duration of high temperature stress that decreases floret fertility and individual grain weight, and (iii) quantify impact of high daytime temperature during floret development, flowering and grain filling on reproductive traits and grain yield under field conditions. Periods between 10 and 5 d before anthesis; and between 5 d before- and 5 d after-anthesis were most sensitive to high temperatures causing maximum decreases in floret fertility. Mean daily temperatures >25°C quadratically decreased floret fertility (reaching 0% at 37°C) when imposed at the start of panicle emergence. Temperatures ranging from 25 to 37°C quadratically decreased individual grain weight when imposed at the start of grain filling. Both floret fertility and individual grain weights decreased quadratically with increasing duration (0-35 d or 49 d during floret development or grain filling stage, respectively) of high temperature stress. In field conditions, imposition of temperature stress (using heat tents) during floret development or grain filling stage also decreased floret fertility, individual grain weight, and grain weight per panicle.

No MeSH data available.


Related in: MedlinePlus