日照长度对三类唐菖蒲开花,生长的效应

EFFECT OF DAYLENGTH ON FLOWERING AND GROWTH OF THREE GARDEN RACES OF GLADIOLUS

Three garden races of gladiolus were grown in a glasshouse at 4 daylength regimes which involved 8 hours ( covering plants with black cloth), 14 hours (natural daylength), 20 hours and 24 hours (prolonging natural daylength with incandescent lamps or high pressure sodium lamps) . Compared with flowering, cv. Peter pears ( large-flowering) and cv. Rose charm ( small-flowering ) were sensitive to daylength. Short day ( 8 h ) resulted in all plants of cv. Peter pears blasting and cv. Rose charm serious flower-bud abortion. However, cv. Roselind (intermediate-flowering)was insensitive to daylength. The 8h daylength promoted its slightly earlier flowering but poorer inflorescence quality. Long day ( 14~16h or more ) generally enhanced stalk and spike elongation and increased the number of florets per spike. There also existed difference in growth respondence to photoperiod among the three garden races. The 8h short daylength almost did not affect leaf growth of cv. Peter pears, but promoted new corms and roots to grow sharply. As to cv. Roselind, the leaf and new corm growth was inhibited^ significantly by 8h daylength treatment, whereas root was not in fluenced. In small-flowering cv. Rose Charm, the growth of leaf, new corm and root were all inhibited seriously by 8h short daylength. The best growth of cv. Peter pears was observed under 14~16h daylength, while cv. Rose charm grew best under 20h daylength.