The effects of wind on pollen flow depending on insect pollinators in entomophilous carrot (Daucus carota L.) plants were studied in a field, where two (2) species of syrphids (Sphaerophoria spp.) were the major pollinators and east wind of 2.5m/sec was the most common. Three (3) stecklings of the yellow root line, which is dominant to the orange root line, were planted as pollen donors at the center of the field. The pollen donors were surrounded by 12 stecklings of the orange root line as the seed parents planted at 0.5m intervals from the center in every eight directions arranged radially (Fig. 1). Seeds of two (2) flower umbels of five (5) seed parents close to the pollen donors in each direction were separately harvested and sown in a field for the estimation of the crossing rate based on the root color ratio. The two (2) flower umbels were well synchronized with anthesis of the pollen donors.
The crossing rates of the seed parents for the south and north directions at 0.5m from the center of the pollen donors were 61.4% and 82.8%, respectively, while 36.9% and 4.8% for the east and west directions, respectively (Table 1). Furthermore, the crossing rate decreased to 5-6% at a distance of more than 1.5m from the pollen donors. It was demonstrated that the main area of the pollen flow is rather small and main direction of the pollen flow forms a right angle to the wind direction when Sphaerophoria spp. are the major insect pollinators (Fig. 2).
It is concluded that in order to increase the amount of F₁-seeds, the layout of planting rows of parental lines should be carefully considered in terms of planting width of the male-sterile seed parent and pollen donor as well as wind direction and visiting pollinators in the field.

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Temperature is an important factor that influences the growth of plant individuals and plant tissues in vitro. Plant individuals often grow better under different day and night temperature conditions than under constant day and night temperature conditions. However, plant tissues in vitro are usually cultured at constant day and night temperatures and in most of the cases, rice anther culture is conducted at temperatures in the range of 25 to 28°C. In this study, experiments were focused on the effects of different day and night temperatures on callus induction and plant regeneration from anthers. Four Japonica rice cultivars were used. Anthers including mid- to late uninucleate pollen grains were incubated in growth chambers that provided about 3, 000 lx of fluorescent light under a 12 hr photoperiod. The frequencies of callus formation and plant regeneration were examined by using two chambers controlled at day -30°C/night -20°C (30/20°C) and 25/25°C with the daily average temperatures being synchronized. When the anthers of a cultivar ‘Kitaake’ were inoculated on liquid medium, in the 30/20°C culture the rate of callus induction per anther significantly increased, with an average value of 102% for the four years tested, compared with 53% for the 25/25°C culture. In addition, for the calli induced at 30/20°C, the frequency of albino plant differentiation decreased compared with that at 25/25°C. The effect of the 30/20°C culture on the increase of the callus formation rate was recognized in the other three cultivars ‘Kirara397’, ‘Yukihikari’ and ‘Aya’, too. Moreover, such effect was revealed not only in liquid medium but also on solid medium. The frequency of green plant regeneration from calli increased when the calli were cultured at 30/20°C during the regeneration period. When anthers were cultured at 30/20°C throughout the period from anther inoculation to plant regeneration, the rates of callus formation per anther, of the calli that regenerated green plants and of green plant regeneration per anther were 96%(1.6times of that at 25/25°C), 42%(1.4times) and 41%(2.4times), respectively, as an average of six experiments including different cultivars and years. The 30/20°C culture is recommended as an effective method for increasing the yield of haploid plants from rice anther.

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