Impact of high temperature on pollen germination and spikelet sterility in rice: comparison between basmati and non-basmati varieties

Abstract

Increased temperature due to global warming may reduce pollen germination and induce spikelet sterility in rice crops. Anthesis is the most sensitive stage in rice and exposure to high temperature during this period may cause reduction in floral reproduction. Increased temperature will have different effects on different rice varieties. In the present study the effect of high temperature on pollen as well as on spikelet sterility in basmati (aromatic) and non-basmati (non-aromatic) rice varieties was quantified. Rice varieties were grown at 11 different sowing dates, to see the effect of varying temperature on pollen and spikelet sterility. Rise in temperature increased pollen sterility and reduced germination of pollen grains on the stigma. Temperature above 338C during anthesis gradually increased pollen sterility in all rice cultivars. At 35.58C, variety Pusa Sugandh 2 (basmati) recorded a pollen sterility of 17% and 26% reduction in pollen germination. The principal cause of sterility was reduced anther dehiscence and less pollen deposition on the stigma at higher temperature. Increased temperature during the grain-filling period also increased spikelet sterility in rice and variety Pusa Sugandh 2 was most affected. Nonbasmati rice varieties were less affected by increased temperature than basmati types. The study indicated that increasing temperature could limit rice yield by affecting pollen germination and grain formation. It also suggested that sensitivity of pollen grains to temperature damage could be taken as one of the most important parameters for predicting rice yield in warmer climates.Additional keywords: pollen sterility, basmati rice.

Comparative Performance of Hybrid and Elite Inbred Rice Varieties with respect to Their Source‐Sink Relationship

“…The percent of fertile spikelets gradually declines when daily mean temperature exceed 29°C [ 50 ] or 29.6°C [ 51 ]. Chakrabarti et al [ 52 ] reported that pollen sterility gradually increased above 33°C. In spite of prevailing normal temperature one week before and after of flowering (data not shown) and normal appearance of spikelets, the number of filled grain as a percentage declined rapidly in studied hybrid varieties than in inbred BRRI dhan45 at delayed planting.…”

Physiological Traits for Shortening Crop Duration and Improving Productivity of Greengram (Vigna radiata L. Wilczek) Under High Temperature

“…By contrast, multiple abnormalities were detected in pollen tubes of the heat-sensitive genotype LGG 460, where the emergence of multiple tubes, and their bursting and coiling were observed; eventually, the pollen failed to germinate at temperatures exceeding 40°C ( Figure 10 ). Earlier reports on rice have also indicated that an increase in temperature could limit yield by affecting pollen germination and grain formation (Endo et al, 2009; Wassmann et al, 2009; Chakrabarti et al, 2010). The male gametophyte is particularly sensitive to HTs at all stages of development, while the pistil and the female gametophyte are considered to be more tolerant (Hedhly, 2011).…”

Efectos de la disminución de temperatura sobre el desarrollo de la pared de la antera y el grano de polen en Oryza sativa L.

“…indica bajo condiciones de alta temperatura. En este sentido Chakrabarti et al (2010) evaluaron el efecto de alta temperatura (28-34 ºC) sobre la viabilidad del polen de diferentes variedades de arroz de la subsp. indica y observaron que el aumento de temperatura incrementó la esterilidad del polen y redujo la germinación de los granos sobre el estigma.…”