Wetland irises are highly valued for their vibrant flowers and strong adaptability, making them important ornamental plants with broad applications in landscaping. However, their cultivation is often constrained by inefficient propagation. The application of plant growth regulators (PGRs) in wetland irises remains limited. This study systematically examined the effects of different concentrations of 6-benzylaminopurine (6-BA; 1,000 and 2,000 mg/L), and prohexadione-Ca (PC; 500 and 1,000 mg/L) on key growth parameters of three wetland iris species: Iris ensata, Iris ensata var. variegata, and Iris sanguinea. Specifically, the study focuses on evaluating the impacts of these PGRs on bud number, plant height, rhizome diameter increment, rhizome weight, and flowering performance. Quantitative analyses of the physiological and morphological responses of these species to PGR treatments revealed distinct, species-specific responses to PGR treatments. Low concentrations of PC increased bud number by up to 0.75 and flower number by 0.47 per plant in I. ensata, while high concentrations of both regulators significantly reduced plant height and rhizome enlargement, particularly in Iris ensata var. variegata and I. sanguinea. These findings provide critical insights for optimizing cultivation practices of wetland irises and also contribute to both theoretical knowledge and practical guidelines for leveraging PGRs to improve the ornamental and functional traits of these plants in landscape applications.

Hydrangea macrophylla is a popular ornamental shrub with a lot of economic and aesthetic value. It is known for its different flower shapes (lacecap and mophead) and the way its flowers change color depending on the pH of the soil. Even though it is important for gardening, we still don’t know much about the molecular processes that lead to flower growth. The purpose of this study was to find and study SNP-related genes and transcription factors that are connected to the growth of H. macrophylla flowers. Genome-wide SNP analysis identified 11 SNPs associated with MYB transcription factors and 10 SNPs linked to a MADS-box SEP1 gene, highlighting their potential role in inflorescence-type regulation. These SNPs provide genomic resources for functional validation and marker-assisted breeding in Hydrangea macrophylla. We found the MYB and MADS-box gene families, which are important for pigmentation and flower organ identity, through an analysis of the transcriptome and gene expression. The MYB family has 73 1R-MYBs, 105 R2R3-MYBs, and 4 3R-MYBs. The MADS-box family had 42 Type I (M-type) members and 36 Type II (MIKC-type) members. Motif and phylogenetic analysis showed that certain domains were preserved. For example, R2R3-MYBs and MIKC-type MADS genes are grouped with Arabidopsis orthologs, which suggests that their functions are also preserved. There was a clear link between the greatest expression of MADS-box genes and the distinct phases of floral bud differentiation. Some MYB genes, on the other hand, showed alternative expression patterns that may help petals or sepals develop. qRT-PCR validation of representative MYB and MADS-box genes corroborated the transcriptome-based expression profiles, supporting their role in flower development and inflorescence-type regulation.

Embryo abortion at the heart-shaped stage is the main reason for the failure of interspecific hybridization of hydrangea, and salicylic acid plays a key role during embryo abortion. Difficulties in obtaining seeds from interspecific hybridization between Hydrangea macrophylla and H. arborescens had severely restricted the process of breeding new hydrangea varieties. To clarify the cause of reproductive barriers, an interspecific hybridization was made between H. macrophylla 'Endless Summer' (female parent) and H. arborescens 'Annabelle' (male parent). The results showed that both parents’ floral organs developed normally, 'Annabelle' had high pollen viability (84.83

Hydrangea is an evergreen or deciduous shrub or woody vine of the genus Hydrangea Linn. in the Saxifragaceae family. The plants in this genus have large in fl orescences, a lengthy fl orescence, and high ornamental value (US Department of Agriculture -National Agricultural Statistics Service 2014). The Hydrangea cultivars primarily derived from H. macrophylla , H. paniculata , H. arborescens , and H. quercifolia (Khaing et al. 2016). Among these species, H. macrophylla stands out as the most diverse, boasting an impressive collection of more than 1000 cultivars (Wu and Alexander 2019). The cultivars of H. macrophylla exhibit two types of variations in fl ower morphology; one is a semispherical or nearly entirely spherical clusters of showy sterile fl owers possessing visually striking sepals, commonly known as " mop -heads " ; another is fl at clusters of inconspicuous and diminutive fertile fl owers surrounded by a ring of more prominent sterile fl owers, named as " lacecaps. " The cultivars can be applicated in both ground and potted planting, as well as in the production of fresh cut fl owers, dried fl ow- ers, and pressed fl owers (Cerbah et al. 2001). Nevertheless, H. macrophylla cultivars are sensitive to high temperature (Lu et al. 2022) and prone to disease, such as rust, powdery mildew, leaf spot, root rot, and botrytis blight (Park et al. 2012). H. chinensis is a native species in China and Japan, distributes in Anhui Province, Hunan Province, Jiangxi Province, Guangxi Zhuang Autonomous Region, and Taiwan Province in China. Its height is up to 2 m according to the Flora of China. Foliar disease incidence appeared reduced on H. chinensis compared with H. macrophylla , as observed in the nursery. On the leaves of H. macrophylla , there were many necroses caused by disease in Autumn 2017 (Fig. 1A); however, the necrosis was much less on the leaves of H. chinensis in the same year (Fig. 1B). To enhance the stress tolerance of hydrangea cultivars, crossbreeding has been performed between H. macrophylla and H. chinensis . As a result, a novel cultivar known as Luo Xue was successfully produced, with tolerance to high temperatures and foliar disease (Fig. 2B) and a signi fi cant increase in in fl orescence stem rigidity.

短梗冬青(Ilex buergeri)原产于我国,耐修剪,耐寒耐旱,适应性强,实生后代易出现变异.本研究通过对短梗冬青实生群体相关分离的性状进行观测与分析,从实生苗的优良变异中选育冬青优良单株.结果表明:短梗冬青苗童期较长,实生群体的叶型变异丰富,从实生群体中选育出叶型特异、遗传稳定、适应性好的优良单株8个.

以4种常绿冬青(Ilex chinensis Sims)冬青'阿拉斯加'、矮生无刺枸骨、冬青'中国少女'和冬青'纳瑞'为试验材料,研究了4种施肥处理:高氮素肥、高氮素肥+叶面肥(磷酸二氢钾)、高钾素肥、高钾素肥+叶面肥,对不同冬青品种新抽枝条长度、坐果率、果粒径和果实质量的影响.结果发现,与高钾素肥相比,高氮素肥会显著提高冬青'中国少女'新抽枝条长度和冬青'纳瑞'的坐果率,同时会显著降低冬青'阿拉斯加'和矮生无刺构骨的果粒径.后期喷施叶面肥会显著增加冬青'阿拉斯加'果实径大小和质量,显著提高矮生无刺枸骨和冬青'中国少女'新抽枝条长度以及后者的坐果率,但同时也会降低矮生无刺枸骨和冬青'纳瑞'坐果率和果实质量.研究表明,园林生产中应根据不同冬青品种营养需求特点制定合适的肥料配比方案,需要强调的是施用叶面肥应据品种而定.

为了解决绣球属杂交育种和野生资源开发中,无菌播种操作难度大、 污染率高、 萌发率低、 种子损失多的问题,本研究改良了常规无菌播种技术,提出一种操作简单、 高效的绣球无菌播种技术.结果表明,改良无菌播种技术具有操作简单、 污染率低、 种子损失小和萌发率高等优点,能在短时间内获得大量绣球杂交后代和野生资源实生苗,为新品种培育提供筛选群体,可实现标准化、 规模化育种,是绣球商业化育种和野生资源开发利用的基础.

The differential expression of genes is crucial for plant somatic embryogenesis (SE), and the accurate quantification of gene expression levels relies on choosing appropriate reference genes. To select the most suitable reference genes for SE studies, 10 commonly used reference genes were examined in synchronized somatic embryogenic and subsequent germinative cultures of Liriodendron hybrids by using quantitative real-time reverse transcription PCR. Four popular normalization algorithms: geNorm, NormFinder, Bestkeeper and Delta-Ct were used to select and validate the suitable reference genes. The results showed that elongation factor 1-gamma, histone H1 linker protein, glyceraldehyde-3-phosphate dehydrogenase and α-tubulin were suitable for SE tissues, while elongation factor 1-gamma and actin were best for the germinative organ tissues. Our work will benefit future studies of gene expression and functional analyses of SE in Liriodendron hybrids. It is also serves as a guide of reference gene selection in early embryonic gene expression analyses for other woody plant species.

[目的]建立染色体形态良好、分裂相内染色体分散且无细胞质背景的绣球根尖高质量染色体制片技术,完善中期染色体45S rDNA和5S rDNA荧光原位杂交(FISH)技术体系,为深入开展绣球属植物分子细胞遗传学研究奠定基础.[方法]以绣球'无尽夏'当年生半木质化枝条水培长出的幼嫩根尖为材料,分别采用1 MPa一氧化二氮(N2 O)、0.7 mmol·L-1环己酰胺、2 mmol·L-18-羟基喹啉对根尖进行不同时间预处理.预处理后的根尖分生组织在4％纤维素酶和2％果胶酶混合酶液中酶解后进行染色体制片.以45S rDNA和5S rDNA为探针,对中期染色体进行原位杂交.[结果]1)1 MPa一氧化二氮预处理的材料中,预处理0.5 h,大部分中期分裂相染色体较长,浓缩不充分;预处理1 h,染色体浓缩适当,大部分染色体的着丝粒位置可辨;预处理2 h,染色体浓缩过度,呈点状.0.7 mmol·L-1环己酰胺预处理的材料中,预处理1 h和3 h,染色体偏长,浓缩不充分;预处理5 h,染色体浓缩适当,但着丝粒位置显示不明显.2 mmol·L-18-羟基喹啉预处理的材料中,2、4、6 h 3个时间梯度均可得到染色体浓缩适当的材料,各处理时间之间对染色体形态的影响差异并不明显,但着丝粒位置不可辨.综合考虑后认为,绣球根尖预处理的最适条件为1 MPa一氧化二氮预处理1 h.2)3个酶解时间梯度中,酶解0.5 h的染色体制片,中期分裂相和细胞核周围存在明显的细胞质残留;酶解1h的染色体制片,中期分裂相背景干净、染色体分散程度好;酶解2h的染色体制片,观察到很多不完整分裂相,分裂相间无法区分,染色体容易丢失.因此,绣球根尖分生组织在4％纤维素酶和2％果胶酶混合酶液中37℃酶解1 h比较合适.3)绣球'无尽夏'是二倍体,染色体数目为36(2n=2x=36).45S rDNA长、短探针的FISH效果相似,均产生很强的杂交信号,位点位于1对近端着丝粒染色体的短臂末端;5S rDNA长、短探针的FISH信号均较弱,长探针的检出率高于短探针,杂交信号位于1对端着丝粒染色体的长臂末端.[结论]成功建立绣球'无尽夏'根尖高质量中期染色体制备及rDNA物理定位技术体系,该体系可高效确定绣球属植物的染色体数目及rDNA分布,为绣球属资源鉴定、杂交育种的亲本选配提供参考,从而指导绣球属植物的杂交育种实践.

以茶梅‘小玫瑰’、冠盖藤、聚花过路黄和兰花三七4种园林植物1年生苗为试验材料,遮荫处理4个月,研究不同遮荫处理(全光照、遮荫65％、遮荫80％和遮荫95％)对植株生长及生理生化指标的影响,并用隶属函数分析法对4种植物的耐荫性进行了综合评价.结果 表明:茶梅‘小玫瑰’、兰花三七在4种遮荫处理下,4个月后株高均有所增长,但冠幅表现为在遮荫65％和遮荫80％条件下,均有一定的增长,在全光照和遮荫95％条件下为先增长后减小的趋势,冠盖藤覆盖度也出现此现象,聚花过路黄在4种条件下均能生长良好.随着遮荫度增加,4种植物叶片的叶绿素a、b以及叶绿素a+b含量均为先增后减,均高于对照,叶绿素a/b值总体呈现降低趋势;可溶性蛋白质含量均有所降低;相对电导率表现为冠盖藤为先降后增,其余3种植物均为增加的趋势;MDA含量表现为兰花三七为先降后增,其余3种植物均为降低的趋势;POD活性和SOD活性表现为先增后降,除冠盖藤SOD活性表现为先降后增.隶属函数分析法综合评价4种植物的耐荫性,耐荫性顺序为兰花三七＞聚花过路黄＞冠盖藤＞茶梅‘小玫瑰’.

Expanding the southern range of herbaceous peony (Paeonia lactiflora Pall.) is a meaningful and worthwhile horticultural endeavor in the Northern Hemisphere. However, high temperatures in winter seriously hinder the bud dormancy release and flowering of peony in the more southern areas of subtropical and tropical regions. Resource introduction and hybridization can contribute to creating new cultivars with high adaptability in a warmer winter climate. In this study, three representative cultivars of P. lactiflora were screened for flowering capabilities and their annual growth cycles were observed to provide information needed for hybridization. Among these three cultivars, 'Hang Baishao' is the best adapted cultivar for southern growing regions and is unique in its ability to thrive in southern areas of N 30°00'. Pollen viability of 'Hang Baishao' was 55.60% based on five measuring methods, which makes it an excellent male parent in hybridization. Hybrid plants among these three cultivars grew well, but all of their flower buds aborted. Additionally, the ability of three growth regulators that advance the flowering of 'Hang Baishao' to promote an indoor cultivation strategy for improving peony application as a potted or cut-flower plant was tested. 5-azacytidine could impact the growth of 'Hang Baishao' and induce dwarfism and small flowers but not advance the flowering time. Gibberellin A3 promoted the sprouting and growth significantly, but all plants eventually withered. Chilling at 0-4°C for four weeks and irrigation with 300 mg/L humic acid was the optimal combination used to hasten flowering and ensure flowering quality simultaneously. These results can lay the foundation for future studies on the chilling requirement trait, bud dormancy release and key functional gene exploration of herbaceous peony. Additionally, this study can also provide guidance for expanding the range of economically important plants with the winter dormancy trait to the low-latitude regions.

[目的]对来自浙江、江苏、云南和湖南4个大叶榉(Zelkova schneideriana)产地引进的21个大叶榉树家系进行子代测定,研究家系生长性状的遗传变异规律,估算遗传参数,筛选大叶榉树优良家系和单株.[方法]采用多重比较法、综合指数法,结合整齐度指标的联合选择方法进行优良家系筛选,并采用混合线性模型(general-ized linear mixed models,GLMM),以及HalfsibBV程序包计算相应的遗传参数,包括遗传力、遗传相关系数、家系及子代个体育种值.[结果]7年生大叶榉树胸径、树高、枝下高、冠幅和材积的表型变幅分别为6.8～9.5 cm、4.7～7.1m、1.4～2.1m、3.0～4.2m和0.008 2～0.020 6 m3,家系遗传力为0.73～0.87,单株遗传力为0.370～0.817,遗传变异系数为8.35％～24.13％.相关分析表明,除枝下高与调查性状呈中度相关外,其他性状间均为极显著正相关.以30％为入选率,共有8个家系入选,为云10、云15、苏02、苏05、苏14、苏15、湘02和浙07.引入整齐度作为辅助筛选指标,生长性状优良兼顾满足胸径、树高和冠幅整齐度均达80％以上的家系为云10、苏02和苏05.根据育种值选择家系结果与综合选择结果趋势一致,选出来自14个家系的65个优良单株.[结论]大叶榉树各性状在家系间呈极显著差异,家系选育具有很大潜力.采用HalfsibBV软件、综合指数法,结合整齐度指标的联合选择方法可以选出一部分生长优良且一致性高的家系.HalfsibBV软件包可以作为选择优良家系和单株的有效工具.

Enlarging the planting area of economic plants, such as the "Southward Planting of Herbaceous Peony" (Paeonia lactiflora. Pall), is significant for improving people's lives. Peony is globally known as an ornamental because of gorgeous flowers and is mainly cultivated in the temperate regions with relatively cool and dry climates in the Northern Hemisphere. Promoting the landscape application of peony to the lower latitude regions is difficult because of the hot-humid climate. In this study, 29 northern peony cultivars and a unique Chinese southern peony, 'Hang Baishao', were introduced to Hangzhou, located in the central subtropics. Annual growth cycles, resistances and dormancy durations were measured, and crossbreeding between the southern and northern peonies was performed for six years, from 2012 to 2017. Based on data collected from the long-running quantitative observation (LQO), a multi-criteria decision making (MCDM) system was established to evaluate the comprehensive planting performance of these 30 cultivars in the central subtropics. 'Qihua Lushuang', 'Hang Baishao' and 'Meiju' were highly recommended, while 'Zhuguang' and 'Qiaoling' were scarcely recommended for the Hangzhou landscape. This study highlights the dependability and comprehensiveness of integrating the LQO and MCDM approaches for evaluating the introduction performance of ornamental plants.

以粘质土为研究对象,通过田间试验,以传统土壤改良剂泥炭为参考,研究了使用不同配比的竹纤维介质对粘质土理化性质以及植物(翠竹、木犀、紫珠)生长量、成活率和根冠比的影响,结果表明:竹纤维介质通气透水性好,保水性较差,对粘质土的物理性质具有良好的改良效果;采用粘质土∶竹纤维介质∶河沙=8∶1∶1的比例改良粘质土可提高植物的生长量和成活率,使移栽后的植物根冠比快速恢复到正常生长状态,工序简单,成本比泥炭改良降低5％～20％,更适用于园林绿化土壤改良.

[Objective] To solve the problem that Osmanthus fragrans cultivars being hardly identified in nursery stock production and landscape application,this study proposed a classification method based on random forest algorithm and SRAP molecular markers,which can be used for easily,quickly and accurately identifying varieties.[Method] DNA of 45 O.fragrans cultivars were extracted,which were applied to PCR amplification,using 90 SRAP primer pairs.The fragments were examined by Capillary Electrophoresis to screen the primer pairs with high polymorphism level and steady amplification.The amplification data were used to calculate polymorphism information content (PIC),numbers of patterns,numbers of effective patterns,the discriminating power (D),chi-square value of patterns distribution (x2),and pairs of indistinguishable samples (x).The locus data of combination of primer pairs that can discriminate all cultivars were used as training set for construction of classification modes based on random forest algorithm.The models with best classifying ability were selected depending on their generalization ability and classifying quality.[Result] A total of 10 SRAP primer pairs were selected,with mean PIC of 0.26,mean numbers of patterns of 33.9,mean numbers of effective patterns of 26.6,mean D of 0.97,mean x2 of 21.07 and mean x of 28.2.Eight classification models were constructed using 8 combination of 2 prime pairs that can discriminate all cultivars (rf1-rf8).The OOB (out of bag) error rate of these models ranged from 0.004 4-0.013 9.Among of them,rf5 and rf3 had the strongest generalization ability,while rf8 had the weakest.And rf1 had the best classifying quality,rf3,rf4,rf5 and rf7 had better,while rf8 had the worst.[Conclusion] Classification models rfl,rf3,rf4,rf5 and rf7 have the strongest classifying ability,with the combination of SRAP primer pairs of me1/em3 + me9/em6,me4/em5 + me9/em6,me4/em8 + me9/em6,me6/em9 + me9/em6 and me5/em5 + me9/em6,separately.The weaker correlation of selected primer pairs brings the stronger classifying ability of models.The method proposed in this study can be applied to identity O.fragrans cultivars quickly and accurately.

以4种冬青属植物花粉为试验材料,采用正交试验设计,分析了蔗糖、H3BO3和CaCl2组成的液体培养基对冬青花粉萌发率和花粉管生长的影响,筛选出适合4种冬青花粉离体培养的培养基,同时探讨了4℃和-20℃贮藏条件对冬青花粉生活力的影响.结果表明:1)短梗冬青、全缘冬青和大叶冬青适宜的蔗糖浓度为10％,大别山冬青为5％,短梗冬青、全缘冬青适宜的H3BO3浓度为0.002％,大别山冬青和大叶冬青为0.006％,CaCl2促进大叶冬青的花粉萌发和花粉管的生长,但抑制其他3种冬青.2)在4℃和-20℃贮藏条件下,4种冬青花粉随时间的增加萌发率均表现为先升后降,其中短梗冬青和大别山冬青在-20℃贮藏条件下花粉萌发率高于4℃;全缘冬青和大叶冬青花粉贮藏前期萌发率在4℃条件下高于-20℃,贮藏后期在-20℃条件下随着时间增加花粉萌发率下降趋势较4℃缓慢.3)花粉管长度在2种贮藏条件下随时间增加均表现为先增后减,短梗冬青花粉在4℃条件下花粉管长度增减幅度明显,但在-20℃条件下花粉管长度在贮藏56 d无差异变化;全缘冬青、大叶冬青和大别山冬青花粉管在2种贮藏条件下先增后减趋势一致,但-20℃条件下随着时间增加花粉管长度减短趋势较4℃缓慢.4)4种冬青花粉萌发率与花粉管长度均存在一定的正相关性.综合得出,冬青花粉活力个体差异显著;4℃适合冬青花粉短时间贮藏,-20℃更适于冬青花粉的长时间贮藏;根据花期和花粉生活力丧失速度的差异,短梗冬青和全缘冬青适合作为冬青属种间杂交的父本,大叶冬青和大别山冬青适合做母本.

High temperature in summer often leads plants to lose water and even to die,which is a serious problem in application of solid soilless substrate in vertical greening.In order to solve this,the water re-tention of the traditional substrate,the imported solid soilless substrate 'Pafcal',and the domestic solid soilless substrate 'Tan Mian'were compared,and a comprehensive evaluation on the drought adaptability of 7 landscape plants,including Hedera nepalensis ,Trachelospermum asiaticum 'Ougonnishiki',Ligus-trum quihoui Carr.,Ligustrum japonicum 'Howardii',Serissa japonica 'Variegata',Gardenia jasmi-noides cv.prostrata and Ligustrum japonicum 'Jack Frost',were carried out by factor analysis,using drought stress response time,recovery after rewater,endogenous substances content and protective en-zyme activity as indexes.The results showed that:(1 )the traditional substrate had the strongest water retention,and 'Tan Mian'had stronger,while 'Pafcal'had the worst;(2)all of the plants in the tradi-tional substrate had the longest drought stress response time,and which in 'Tan Mian'had longer,while which in 'Pafcal'had the shortest;(3)after rewatering,most plants in traditional substrate recovered much better than that in solid soilless substrates,but H .nepalensis and G.jasminoides cv.prostrata re-covered well in solid soilless substrates;(4)MDA content and POD activity of most pants in all substrates increased firstly and then decreased;SOD activity of H .nepalensis and L.japonicum 'Jack Frost'in'Tan Mian'at 20 d increased markedly,yet which of the other plants showed no significant changes in all substrates;soluble protein content showed the same variation trend in all substrates,which was that H . nepalensis and S .japonica 'Variegata'continuously decreased,while the others increased firstly and then decreased;(5)H .nepalensis ,L.japonicum 'Jack Frost'and Serissa japonica 'Variegata'had extreme-ly strong drought adaptability in the traditional substrate,yet H .nepalensis ,S .japonica 'Variegata' and L.japonicum 'Howardii'had strong drought adaptability in both two solid soilless substrates.

BACKGROUND:The artificial enlargement of the planting area and ecological amplitude of ornamentals for horticultural and landscape applications are significant. Herbaceous peony (Paeonia lactiflora Pall.) is a world-famous ornamental with attractive and fragrant flowers and is mainly planted in temperate and cool areas. Comparatively higher winter temperatures in the subtropical and tropical Northern Hemisphere result in a deficit of chilling accumulation for bud dormancy release, which severely hinders "The southward plantation of herbaceous peony". Studies on the dormancy, chilling requirement (CR) and relevant molecular mechanisms of peony are needed to enhance our ability to extend the range of this valuable horticultural species.RESULTS:Based on natural and artificial chilling experiments, and chilling hour (CH) and chilling unit (CU) evaluation systems, the lowest CR of 'Hang Baishao' was between 504.00 and 672.00 CHs and the optimal CR was 672.00 CHs and 856.08 CUs for achieving strong sprouting, growth and flowering performance. Transcriptome sequencing and gene identification by RNA-Seq were performed on 'Hang Baishao' buds during the dormancy and sprouting periods. Six gene libraries were constructed, and 66 temperature- and photoperiod-associated unigenes were identified as the potential candidate genes that may regulate or possibly determine CR characteristics. The difference in the expression patterns of SUPPRESSPOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) between the winters of 2012-2013 and 2015-2016, and the difference of CR fulfillment periods also between these two winters represented the interesting congruent relationships. This correlation was also observed for WRKY DNA-BINDING PROTEIN 33 (WRKY 33).CONCLUSIONS:Combined with the results acquired from all of experiments, 'Hang Baishao' was confirmed to be a superb peony resource that have significantly low CR characteristics. The two genes of SOC1 and WRKY33 are likely involved in determining the CR amount and fulfillment period of 'Hang Baishao'. HEAT SHOCK PROTEIN, OSMOTIN and TIMING OF CAB EXPRESSION 1 also deserve attention for the CR research. This study could contribute to the knowledge of the deep factors and mechanisms that regulate CR characteristics, and may be beneficial for breeding new germplasms that have low CRs for landscape or horticulture applications in subtropical regions.