Research On Selection Of Small Potted Chrysanthemum From Cut Cultivars And Their Photosynthetic Characteristics

Two new chrysanthemum varieties ‘Ziban’, ‘Zilian’ and eight traditional cutflower cultivars ‘Xintaihong’,‘Fensimao’, ‘Lvju’, ‘Fenying’, ‘Zichun’, ‘Kadina’, ‘Kord’ and ‘Yidianjin’ were used as materials for small potted cultivation in this paper. Based on the study of photosynthetic characteristics and short day treatment characteristics of 10 chrysanthemum cultivars, a comprehensive evaluation system for potted flower varieties was established initially.The effects of CO₂ enrichment on the morphological structure and physiological indexes of ‘Fenying’ were also studied. The main research contents and results were as follows:1. The effects of photoperiod treatment on ten chrysanthemum cultivars, the total sugar, chlorophyll, dry weight / fresh weight and flowering traits were sudied. The results showed that the bud time of all cultivars was earlier than that of control group by short day treatment and short day treatment promoted the flowering of potted chrysanthemum cultivars. The chlorophyll content, total sugar content, dry weight / fresh weight were all higher than the control group. Short day treatment promoted the accumulation of leaf nutrients content and the quality of small-sized potted chrysanthemum plant type. 2.The light response and photosynthetic parameters of 10 chrysanthemum cultivars were studied. The results indicated that maximum net photosynthetic rate from large to small were sorted, ‘kord’（22.88）> ‘Fenban’（22.75） > ‘Lvju’（21.57）> ‘Fensimao’（20.42）>‘Zichun’（20.24）>‘Zilian’（19.77）>‘yidianjin’（18.72）>‘Fenying’（17.26）>‘Xintaihong’（16.64）>‘Kadina’（16.50）, Light saturation point from large to small order, ‘kord’（1696）>‘Lvju’（1380）>‘Fensimao’（1216）>‘Yidianjian’（1068）>‘Zichun’（1012）>‘Kadina’（1016）>‘Zilain’（996）>‘Fenban’（896）> ‘Xintaihong’（632）>‘Fenying’（616）, Light compensation point from large to small order, ‘Fenban’（76）>‘Yidianjian’（72）>‘Kadina’（72）>‘Lvju’（36）>‘Zilain’（32）>‘kord’（32）>‘Xintaihong’（28）>‘Fenyin’（24）>‘Fensimao’（24）>‘Zichun’（20）。The less maximum net photosynthetic rate and light saturation point showed that plants had higher light utilization rate. Chrysanthemum cultivars which had the less light compensation point had stronger adaptability to shade indoor environment.4. 3. Ten varieties of cut chrysanthemum were evaluated to pot chrysanthemum by Analytic Hierarchy Process（AHP） evaluation system which were combined by 14 second level evaluation indicators belong to the three first level indicators. The weight value of5.various indicators were calculated by AHP method. The results showed that color weight value was the highest, 0.2563, followed by plant height, 0.2429, the third double flower 0.1197, other indicators of the weight values from big to small order were crown width 0.0868, leaf number 0.0649, flowers dense degree 0.0535, hormone sensitive 0.0535, stem diameter 0.0377, length of flower neck 0.025, natural flowering 0.0238, merits 0.0223, photoperiod sensitivity 0.0139, susceptibility to diseases and insects 0.0081, low temperature sensitivity 0.0048, respectively. Then scoring each traits according to the evaluation criteria and calcula-ting comprehensive score of each variety, results showed that comprehensive score were ordered as ‘Fenying’（4.4211）> ‘Xintaihong’（4.1795）> ‘Lvju’（4.0047）>‘Zilain’（3.9565）>‘Fensimao’（3.5423）>‘Fenban’（3.5521）>‘Kadina’（2.7069）>‘kord’（2.3307）>‘Zichun’（2.2807）>‘Yidianjin’（1.7977）。The effect of CO₂ fertilization on chrysanthemum cultivar ‘Fenying’ which was the best potted chrysanthemum cultivars screened by AHP method was studied. Results show that, plant height, leaf number, stem diameter and othermorphological index were significantly increased by CO₂ enrichment treatment. The Chla/Chlb of two treatment significantly less than that of CK and improved the ability of plants to absorb and utilize the weak light. The results of microscopic observation showed that the pores developed on the upper leaf surface, higher stomatal density, stomatal area and fur on the lower leaf surface because of CO₂ enrichent treatment.