Study On Biological Characters Of Iris Lactea Pall.Var. Chinensis (Fisch.) Koidz.

Iris lactea Pall. var. chinensis (Fisch.) Koidz. is abundant and wide distribution in Iris, which has developed roots and a very long green period, noblest flower, moderate height. It has strong tolerance to drought, heat, cold, salt and alkali. It is used in urban virescence, sand-fixation, salina meliorate, and garden virescence in the cities with poor water. The systematic research on its growing periods and the biological character can provide theoretic directions and technical supports in the fields of breeding, reproducing and its application in gardens. This paper, using biological methods of grassland which made the introduction experiment stations seed germination and biological characteristics, seedling growth process, flowering characteristics analyzed and studied. The main results are as follows:1. Iris lactea var. chinensis seed has different germination ability in the three periods:milk stage, dough stage and full ripe stage. Most seeds at milk stage get rotten totally without ability to germinate; seeds at dough stage can germinate and the germination rate comes to 80%; seeds at full ripe stage begin to dormancy, germination rate is very low. There is little difference among the seeds in upper, middle and lower positions in the capsule.2. The permeability of seed capsule was poor and its mechanical hinder also was hard, which were the main causes of seed dormancy; the albumen of its seed affect germination; the germination of seed embryos proved that the embryo was not dormant itself; the measuration of endogenic inhibitors showed that the extracts of seed capsule and albumen strongly inhibited the growth of cabbage seedlings.3.15℃and 30℃are not adaptive to germinate and the most adaptive temperature range to Iris lactea var. chinensis is from 20℃to 25℃. In addition, the alternative temperature change can redound to the germination of seeds in Iris. Cut part of the albumen can get a higher germination rate4. The cotyledon of Iris lactea var. chinensis seedling bourgeons under earth, seedlings only remain ligular sheath and basal completely degenerated, and neck extend downward until completely joint with hypocotyl forming mesocotyl.5. Iris lactea var. chinensis's florescence can last more than 35 days, one flower can last 63.8 hours, single plant florescence lasts 20 days more or less. It usually blossom out from top to root, the second flower will blossom out in the next day after the first flower was withered.