Pollen Production, Microsporangium Dehiscence and Pollen Flow in Himalayan Cedar (Cedrus deodara Roxb. ex D. Don)

Abstract

Microsporangium dehiscence, pollen production and dispersal were studied in Himalayan cedar (Cedrus deodara) during 1998 and 1999. Microsporangium dehiscence showed diurnal periodicity and was found to be related to air temperature and relative air humidity, with a strobilus taking 2 d to dehisce completely in warmer conditions and 3 d in cooler ones. The frequency of flowering in C. deodara was highly variable during the two successive years; however, cyclical production of pollen grains was observed in 50% of the trees. The maximum concentration of pollen grains in the air was found between 1200 and 1600 h, and this period was also noted to be the best time for pollination. Studying migration of pollen grains from isolated single trees in three directions showed that migration was not uniform in all directions. Long-distance transport of pollen grains was observed in the downhill direction. However, in the uphill and horizontal directions grains could travel only up to 97.5 and l95.1 m, respectively, and the frequency of pollen grains to the source frequency at these distances was only 1.9 and 2-5%, respectively. The results suggest that an isolation barrier of 190 m may be considered as a minimum for the management of deodar seed orchards.

Effects of environmental factors on pollen production in anemophilous woody species

“…Differences among sampling years as well as higher pollen production from lower stations and southern directions are reported for various species (Fotiou et al 2010;Guardia and Belmonte 2004;Jato et al 2007a;McKone 1990;Moe 1998). Plasticity in pollen production is largely manifested under different environmental factors (LaDeau and Clark 2006;Rogers et al 2006;Wan et al 2002;Wayne et al 2002;Ziska and Caulfield 2000) and has been reported for herbaceous and woody species from different climatic zones: for Alnus incana (Moe 1998), Betula alba (Jato et al 2007a), Cedrus deodara (Khanduri and Sharma 2002a), Chionochloa pallens (McKone 1990), O. europaea (Ferrara et al 2007), Parietaria judaica (Fotiou et al 2010;Guardia and Belmonte 2004), Pinus roxburghii (Khanduri and Sharma Corylus avellana 900 m, S 190.2 (±8.0) 5.6 9 10 3 (±1.2 9 10 3 ) 1.1 9 10 6 (±0.1 9 10 6 ) 5.4 9 10 2 (±1.2 9 10 2 ) 0.3 9 10 1 (±0.1 9 10 1 ) 3.2 9 10 6 (±0.8 9 10 6 ) 900 m, N 219.1 (±7.0) 2.7 9 10 3 (±0.5 9 10 3 ) 5.7 9 10 5 (±0.6 9 10 5 ) 1.2 9 10 3 (±0.2 9 10 3 ) 0.5 9 10 1 (±0.1 9 10 1 ) 3.1 9 10 6 (±0.8 9 10 6 ) Cupressus sempervirens var. horizontalis 90 m, plateau 19.9 (±0.3) 1.9 9 10 4 (±0.1 9 10 4 ) 3.8 9 10 5 (±0.2 9 10 5 ) 2.1 9 10 5 (±0.2 9 10 5 ) 1.0 9 10 4 (±0.1 9 10 4 ) 4.0 9 10 9 (±0.5 9 10 9 ) 450 m, plateau 16.3 (±0.3) 2.1 9 10 4 (±0.3 9 10 4 ) 3.3 9 10 5 (±0.3 9 10 5 ) 9.2 9 10 4 (±0.9 9 10 4 ) 5.5 9 10 3 (±0.5 9 10 3 ) 2.0 9 10 9 (±0.3 9 10 9 ) 450 m, S 17.5 (±0.3) 1.8 9 10 4 (±0.2 9 10 4 ) 2.9 9 10 5 (±0.2 9 10 5 ) 1.2 9 10 5 (±0.1 9 10 5 ) 7.1 9 10 3 (±0.3 9 10 3 ) 2.2 9 10 9 (±0.3 9 10 9 ) 450 m, N 17.0 (±0.3) 2.0 9 10 4 (±0.2 9 10 4 ) 3.1 9 10 5 (±0.2 9 10 5 ) 7.4 9 10 4 (±1.2 9 10 4 ) 4.3 9 10 3 (±0.6 9 10 3 ) 1.8 9 10 9 (±0.3 9 10 9 ) Cupressus sempervirens var.…”

Use of Quercus ilex subsp. ballota phenological and pollen-production data for interpreting Quercus pollen curves

“…Khanduri et al (2002) have suggested that the long-distance transport of Pinus roxburghii pollen is easier downhill than uphill. Similarly, transport upstream appears to have been more favored in the present study, prompting an increase in Q. ilex subsp.…”

Microclimatic-induced fluctuations in the flower and pollen production rate of olive trees (Olea europaeaL.)

“…Allison, 1990;Khanduri & Sharma, 2002) and angiosperms (e.g. Tormo Molina et al, 1996;Gómez-Casero et al, 2004;Rovira & Tous, 2005) show that pollen production heavily depends on many different factors such as available resources, soil and environmental conditions and varies considerably among anemophilous species.…”