东方百合‘Sorbonne’原生质体培养初步研究

百合原生质体培养对百合远源杂交育种具有重要意义。本研究以东方百合‘Sorbonne’花托为外植体，诱导胚性愈伤组织，并对其原生质体提取和培养进行初步研究。结果表明：MS＋Picloram 3mg／L为胚性愈伤组织诱导最佳培养基；胚性愈伤组织在酶解液为2％纤维素酶R-10＋0．5％离析酶R-10＋0．05％果胶酶Y23＋147mg／L二水合氯化钙＋976mg／L2-吗啉乙磺酸＋0．6mol／L甘露醇，酶解12h，制备的原生质体产量最高达4×10^5个／mL，活性达52％；在胚性愈伤组织诱导培养基中进行原生质体的悬滴培养、液体培养、固体培养、固液结合培养和看护培养。结果表明，看护培养是最佳培养方法，并在改良MS＋Picloram 2mgm的培养基中培养2～3d观察到长细胞壁的原生质体，培养4～6d，可见原生质体的第一次分裂，培养40-45d，观察到原生质体分化成的细胞团。

东方百合‘Sorbonne’鳞片离体培养研究

以东方百合品种‘Sorbonne’鳞片为外植体,研究不同因子对‘Sorbonne’消毒、诱导、增殖、生根等的影响。结果表明：‘Sorbonne’外层鳞片消毒最为困难,而中层和内层差异不大；最佳消毒方法是外层鳞片用75%酒精处理30 s再用0.1%升汞浸泡18～20 min；中层和内层鳞片用75%酒精处理30 s,再用0.1%升汞浸泡14～16 min,其中不同部位鳞片诱导率从高到低分别为外层跃中层跃内层,其中外层的诱导率为76.7%；百合鳞片最佳增殖培养基为MS＋6-BA 2.0 mg/L＋NAA 0.2 mg/L,增殖系数为6.8；最佳生根培养基为1/2MS＋6-BA 0.5 mg/L＋NAA 0.2 mg/L,平均生根数为20条。

Chlorocholine chloride and paclobutrazol treatments promote carbohydrate accumulation in bulbs of Lilium Oriental hybrids 'Sorbonne'

The present study was to test the hypothesis that the plant growth retardants chlorocholine chloride(CCC) and paclobutrazol(PBZ)could improve the carbohydrate accumulation in lily bulbs by enhancing photosynthetic capacity and changing endogenous hormones.Plants of Lilium Oriental hybrids'Sorbonne'were treated with a foliar spray of CCC or PBZ(both at 300 mg/L)solution,at six weeks after planting(6 WAP).The morphological parameters,endogenous hormone contents(gibberellic acid(GA),abscisic acid(ABA),and indole-3-acetic acid(IAA)),and carbohydrate contents were measured from 6 to 18 WAP,at 2-week intervals.The results showed that CCC increased the biomass of leaves and stems which might produce more photoassimilates available for transportation and utilization.However,PBZ treatment suppressed vegetative growth and favored photoassimilate transportation into bulbs.A slight delay of bud and anthesis formation was observed in both treated plants.CCC and PBZ treatments substantially enhanced the sucrose contents in leaves probably due to the increase of chlorophyll contents.Treatment with CCC or PBZ decreased GA but increased IAA contents in lily bulbs which might stimulate starch accumulation and formation of new scales.Our experiment suggested that CCC or PBZ treatment is an effective method to promote carbohydrate accumulation in lily bulbs.

Low humic acids promote in vitro lily bulblet enlargement by enhancing roots growth and carbohydrate metabolism

Bulblet development is a problem in global lily bulb production and carbohydrate metabolism is a crucial factor. Micropropagation acts as an efficient substitute for faster propagation and can provide a controllable condition to explore bulb growth. The present study was conducted to investigate the effects of humic acid （HA） on bulblet swelling and the carbohydrate metabolic pathway in Li/ium Oriental Hybrids ＇Sorbonne＇ under in vitro conditions. HA greatly promoted bulblet growth at 0.2, 2.0, and 20.0 mg/L, and pronounced increases in bulblet sucrose, total soluble sugar, and starch content were observed for higher HA concentrations （_〉2.0 mg/L） within 45 d after transplanting （DAT）. The activities of three major starch synthetic enzymes （including adenosine 5＇-diphosphate glucose pyro- phosphorylase, granule-bound starch synthase, and soluble starch synthase） were enhanced dramatically after HA application especially low concentration HA （LHA）, indicating a quick response of starch metabolism. However, higher doses of HA also caused excessive aboveground biomass accumulation and inhibited root growth. Accordingly, an earlier carbon starvation emerged by observing evident starch degradation. Relative bulblet weight gradually decreased with increased HA doses and thereby broke the balance between the source and sink. A low HA concentration at 0.2 mg/L performed best in both root and bulblet growth. The number of roots and root length peaked at 14.5 and 5.75 cm respectively. The fresh bulblet weight and diameter reached 468 mg （2.9 times that under the control treatment） and 11.68 mm, respectively. Further, sucrose/starch utilization and conversion were accelerated and carbon famine was delayed as a result with an average relative bulblet weight of 80.09%. To our knowledge, this is the first HA application and mechanism research into starch metabolism in both in vitro and in vivo condition in bulbous crops.