针对广西钦州产区'桂味'荔枝Litchi chinensis'Guiwei'果园2022年春季坐果后大量出现罕见的"毛笔尖"状畸形果问题,于 2022 年 4 月(谢花时)选择灵山县 4 个发生畸形果较典型的'桂味'荔枝果园及 1 个未发生畸形果对照果园开展田间调查分析,探讨该畸形果形成过程及原因,为荔枝安全使用外源激素促花保果提供参考.调查表明,荔枝畸形果形成从雌花分化柱头伸长即开始异常,后演变成完全无果肉空壳"毛笔尖"状畸形果,这种"毛笔尖"状畸形果不容易脱落且完全丧失商品价值;4个荔枝果园的畸形果株率为94.4%～100.0%,单株畸形果穗率20.0%～24.0%,单穗畸形果粒率60.9%～65.1%,3个指标在4个果园之间差异均不显著.4个果园于控梢促花保果期均使用含苯肽胺酸的"宝赢"产品,其他未使用苯肽胺酸促花保果的对照果园没有畸形果发生.因此,初步认为'桂味'荔枝在当年气候条件下成花坐果期间对苯肽胺酸比较敏感,能使雌花柱头拉长异常而影响授粉受精和果实发育,最终形成无食用价值的空壳畸形果.

【Objective】The main purpose of the study was to screen out the varieties with good compatibility and fine fruit traits grafted on air layering litchi cv.‘Huaizhi’ plants as rootstock, and provided theoretical basis for the optimization and adjustment of the structure of litchi varieties.【Method】The 25-year-old ‘Huaizhi’ plants were selected as rootstocks, and 35 litchi varieties（fine seedlings） such as ‘Xinqiumili’‘Qiongli No.1’ and ‘Guiwei’ were used as scions for top grafting.After grafting for 4 years, the compatibility of rootstock and ear combination was evaluated comprehensively according to grafting survival rate, grafting healing status, growth potential and leaf color, and fruit quality indexes such as single fruit weight, vertical and horizontal diameters of fruit, edible rate and soluble solid content were determined and analyzed, so as to select litchi varieties suitable for high grafting of ‘Huizhi’.【Result】Among the compatibility indexes of litchi varieties grafted on ‘Huaizhi’,the survival rate, rootstock to scion ratio and field compatibility constants（FCC） were 19.44%-66.43%,1.02-1.26 and 1.88-2.22,respectively.Among them, the variety with the highest grafting survival rate was ‘Xinqiumili’,which was significantly higher than that of ‘Guili No.1’‘Beitonghong’ and ‘Yingshanhong’（P＜0.05,the same as below）;The variety with the highest rootstock to scion ratio was ‘Hehuadahongli’,which was significantly higher than that of ‘GLL-2’‘Guili No.1’ and ‘Xinqiumili’;The variety with the highest FCC was ‘Feizixiao’,which was significantly higher than that of ‘Xinqiumili’‘Qiongli No.1’ and ‘Nuomici’.Among the growth indexes of litchi varieties grafted on ‘Huaizhi’,the stock diameter, scion diameter, scion length and branch grade were 3.16-6.81 cm, 2.89-6.11 cm, 1.12-2.40 m and 5.17-9.58 grades respectively after 4 years.Among them, the variety with the highest stock diameter was ‘Hehuadahongli’,which was significantly higher than that of ‘Shuangjianyühebao’‘Qiongli No.1’ and ‘Baitangying’;The variety with the highest scion diameter was ‘Miaozhongnuo’,which was significantly higher than that of ‘Shuangjianyühebao’‘Qiongli No.1’ and ‘Yingshanhong’;The variety with the highest scion length was ‘Tangxiahong’,which was significantly higher than that of ‘Qiongli No.1’‘Shuangjianyühebao’ and ‘Xianpoguo’;The variety with the highest branch grade was ‘Xianjinfeng’,which was significantly higher than that of ‘Yijinqiu’‘Shuangjianyühebao’ and ‘Baitangying’.There were close correlation between graft compatibility and growth indexes.Among the 35 varieties（fine seedlings）,22 varieties had bear normal fruit.The average fruit weight, edible percentage and total soluble solids were 15.97-39.50 g, 62.26%-83.93% and 16.53%-20.67%,respectively.Among them, the variety with the highest fruit weight was ‘Maguili’,which was significantly higher than that of ‘Jiangkouli’‘Miaozhongnuo’ and ‘Yütanmili’;The variety with the highest edible percentage was ‘Guanyinlü’,which was significantly higher than that of ‘Guizaoli’‘Luzhouguiwei’ and ‘Hushanwanli’;The variety with the highest total soluble solids was ‘Feizixiao’,which was significantly higher than that of ‘Dadingxiang’‘Xianpoguo’ and ‘Huaizhi’.Fruit maturity was from June 3 to July 25.Among them, the earliest mature variety was ‘Guizaoli’,and the latest mature variety was ‘Maguili’.【Conclusion】Twenty-two litchi varieties, such as‘ Xinqiumili ’‘Feizixiao’ and ‘Caomeili’,had a high survival rate of grafting with ‘Huaizhi’.After grafting, the growth was good, and the fruit quality and maturity stage were diverse.In production, suitable scion varieties and ‘Huaizhi’ could be selected according to the market demand for high grafting.Compatibility of ‘Beitonghong’ was poor, compatibility of ‘Qiongli No.1’‘Shuangjianyuhebao’ and ‘Baitangying’ was general, and failed to bear fruits and should not be top grafting with ‘Huaizhi’.

研究'桂味'荔枝采后基枝修剪程度对采后枝梢生长和次年结果的影响,对指导荔枝采后修剪管理,实现高产优质高效益生产具有重要意义.田间调查'桂味'荔枝采后基枝3种不同直径粗度范围(Φ≤5mm、5mm＜Φ＜10mm和Φ≥ 10mm)的修剪口共143个,测量其上抽生的216条枝梢生长及结果状况.结果显示,修剪口上抽生的采后枝梢数量、构成单条枝梢的梢次数、枝梢长度、基部径粗、复叶张数、小叶片数及挂果粒数均随其直径增加而增加,尤其以枝梢长度(平均10.64cm增加至平均16.94cm和平均29.70cm)和挂果粒数(平均0.72粒增加至3.35粒和12.61粒)增长最为显著.此外,同梢次结果母枝生长状况和挂果粒数也随修剪口直径增加而显著增加.研究结果表明,'桂味'荔枝采后修剪口径粗显著影响其采后枝梢的生长和次年结果状况,采后基枝修剪到Φ≥10mm粗度,更利于'桂味'荔枝丰产稳产和高效益.

对新发现的特早熟龙眼实生变异单株"桂丰早",采用主栽品种"石硖""储良"作为对照品种进行SCoT分子标记鉴定,并在广西南宁、大新、龙州、钦州和广东茂名、湛江等不同产区布置开展区域引种试验.通过连续4年多点种植观察和分析测试,结果表明:"桂丰早"龙眼与"石硖""储良"对比,在植物学性状、生长结果习性、SCoT分子标记不同引物扩增带均具有明显的差异;"桂丰早"龙眼适应性强,在各地均表现特早熟性状稳定,不同年份不同产区均比同一果园的"石硖"早熟7～15 d,且早结性、丰产性强,果大质优,综合性状优良,认为"桂丰早"适合我国龙眼主产区推广种植,以期缓解目前我国龙眼品种结构不合理、熟期过于集中、效益不好等严重制约产业发展的瓶颈问题."桂丰早"于2021年12月30日获植物新品种授权命名.

为丰富广西龙眼种质资源及为龙眼种质创新利用提供参考,从海南省引进热带生态型"红皮龙眼"种苗在南宁试种,取其枝条与2年生"广眼龙眼"实生苗嫁接,以嫁接热带生态型品种"四季蜜龙眼"为对照,连续3年观察,对比两个品种形态特征和生物学特性,测定其果实品质,分析其在南宁的种植适应性.结果表明,在南宁,"红皮龙眼"极易成花,能正常结果,适应性较好,叶片、花和果实均呈红色,果实9月上旬成熟,未发现病虫为害;单果质量16.30 g,可溶性固形物含量25.7％,分别比"四季蜜龙眼"显著提高77.75％和14.22％(p＜0.05);可食率稍低,果肉细嫩,香气浓郁,风味较佳,属于特大果形晚熟稀有龙眼品种,可在广西相同气候区试验推广,也可作为育种材料加以创新利用.

Lychee is an exotic tropical fruit with a distinct flavor. The genome of cultivar ‘Feizixiao’ was assembled into 15 pseudochromosomes, totaling ~470 Mb. High heterozygosity (2.27%) resulted in two complete haplotypic assemblies. A total of 13,517 allelic genes (42.4%) were differentially expressed in diverse tissues. Analyses of 72 resequenced lychee accessions revealed two independent domestication events. The extremely early maturing cultivars preferentially aligned to one haplotype were domesticated from a wild population in Yunnan, whereas the late-maturing cultivars that mapped mostly to the second haplotype were domesticated independently from a wild population in Hainan. Early maturing cultivars were probably developed in Guangdong via hybridization between extremely early maturing cultivar and late-maturing cultivar individuals. Variable deletions of a 3.7 kb region encompassed by a pair of CONSTANS -like genes probably regulate fruit maturation differences among lychee cultivars. These genomic resources provide insights into the natural history of lychee domestication and will accelerate the improvement of lychee and related crops.

中国是荔枝(Litchi chinensis)的原产地,种植面积和产量规模均居世界第一位,以"岭南果王"著称的中国荔枝在国际鲜果市场享有极高的声誉.荔枝蒂蛀虫(Conopomorpha sinensis)在我国广泛分布于热带南亚热带地区,是荔枝的主要害虫,其幼虫蛀食荔枝果核、果蒂,会影响果实生长发育及商品果率,造成严重的经济损失.荔枝蒂蛀虫的行为隐蔽,世代重叠,难以控制.目前生产上对该虫的控制主要依靠化学防治,但长期使用化学农药容易产生污染环境、药物残留、食品安全以及虫抗药性的问题.本文结合国内外研究进展,着重从荔枝蒂蛀虫生活习性及危害发生规律、预测预报、物理防治、生物防治及生物源农药应用等方面进行综述,并对荔枝蒂蛀虫绿色防控研究方向及以农业防治为基础的综合防治方法进行展望.

龙眼起源于我国南方,适应热带、南亚热带湿热的气候条件,对各类气象条件有较严格的要求.综述了我国科技工作者对龙眼栽培的生态因子,包括温度、水分、日照、风和大气的研究结果,探讨了龙眼不同适宜区域的气候特点,以期为龙眼防灾减灾和生产区划提供理论依据.

为了探索晚熟龙眼品种(系)最佳留树期,以"桂明一号"和优良晚熟龙眼品系"YY-1"(越南引进)为试验材料,测定果实成熟后留树贮藏过程中果实品质及落果率.结果表明,"桂明一号"和"YY-1"两个晚熟龙眼品种(系)的果实可溶性固形物含量达到最高值后14 d,其落果率分别为9.27％、8.74％.果实中葡萄糖、果糖和蔗糖含量在果实成熟前呈增加趋势,在果实成熟时达到峰值;葡萄糖和果糖在果实可溶性固形物含量达到最高值后1周下降较快,14 d后略有升高,蔗糖则一直处于降低趋势.总酸和维生素C含量变化趋势一致,在果实成熟时达到最高,之后1周逐渐下降,果实成熟后14 d达另个峰值,之后迅速下降.综合来看,两个晚熟龙眼品种(系)的最佳留树期为14 d,超过14 d果实品质明显下降.

[目的]观察喷施外源乙烯利及荔枝丰产素对荔枝花穗疏剪效果,并分析其对果实品质和叶片全N含量的影响,为科学合理运用乙烯利和荔枝丰产素进行荔枝疏花及优质高产栽培提供理论参考.[方法]采用单因素随机区组试验设计,桂味荔枝始花期树冠喷洒53 mg/L(T1)、106 mg/L(T2)和160 mg/L(T3)的乙烯利水溶液,以及荔枝丰产素水溶液(T4)和清水(T5,对照),测定脱落的花蕾、枝梗和果实数量,测定果实品质和叶片全N含量.[结果]5个处理的花蕾脱落数和枝梗脱落数排序为T3>T2>T1>T4>T5,果实脱落数总数排序为T5>T4>T3>T1>T2.5个处理对单穗重、果粒数、小横径、果形指数和可溶性固形物含量无显著影响(P>0.05,下同),且肉质、风味、香气、涩味、果肉内膜褐色也无明显差异,但对单果重、可食率和种子重有一定的影响,其中单果重排序为T2>T1>T4>T3>T5,T2处理的单果重(19.45 g)比T5处理(13.68 g)增重42％;T1、T2、T3和T4处理(即乙烯利和丰产素处理)可食率为78％～79％,焦核率为97％～99％,分别较T5处理(清水处理)提高30％～32％和31％～34％.5个处理下叶片全N含量无显著差异,全N含量排序为T2>T1>T4>T3>T5.单果重、果皮重、种子重、可食率、焦核率和可溶性固形物含量与叶片全N含量的相关系数分别为0.886、0.851、0.898、0.739、0.740和-0.947,其中单果重和种子重均与叶片全N含量呈显著正相关(P<0.05,下同);可溶性固形物含量与叶片全N含量呈显著负相关.[结论]乙烯利和荔枝丰产素能对桂味荔枝进行花穗疏剪,且乙烯利一次性喷施浓度106 mg/L能起到最佳控花穗的效果,有效实现省工省力增产的目的,可用于实际生产.

对越南引进的黄皮龙眼种质资源"YN-1"进行观测,研究其在广西南宁的生长表现,对其物候期、植物学性状及果实性状进行评价.结果表明,黄皮龙眼"YN-1"在南宁表现良好,易成花,无冲梢,花期集中在6月中下旬,9月中旬果实成熟,属于晚熟龙眼种质.果实近圆形,果皮浅黄色,光滑;平均单果质量15.31 g,可溶性固形物含量均值25.16％,可食率59.54％;果实完全成熟时总糖、还原糖、维生素C含量分别为188.45 mg/g、82.59 mg/g、678.21 nmol/L,可滴定酸含量为0.05％;留树保鲜时长10d以上(9月15日至9月25日),风味浓甜,香味浓,是一份香气浓、留树保鲜期长的特异龙眼种质资源.

广西荔枝品种历经5个不同发展阶段,广西龙眼品种历经3个不同发展阶段,各个发展阶段的生产情况、特性不同.当前广西荔枝、龙眼产业进入了品种结构调整的新阶段,新品种选育取得较大进展,但存在着前期发展速度过快,品种规划不完善,品种结构不合理,产期集中、经济效益低;新品种选育进展缓慢,育种周期长、效率低等主要问题.应加强育种技术攻关,大力开展杂交育种,选育出更多新品种为生产服务;同时搞好品种规划布局,提高优质品种种植比例,发挥不同产区的气候优势,延长荔枝、龙眼鲜果上市时间,提高生产经营效益.

本文运用实地调查和个别访问的社会调查方法,对越南火龙果产业和科研现状进行调查研究.根据越南农业部最新数据及对越南火龙果产业的调研考察,分析了越南火龙果生产和贸易情况,阐述了越南火龙果产业现状及科研进展情况.结果表明,越南火龙果面积和产量近年来皆呈快速增长趋势,但相关研究相对滞后.虽然发展前景广阔,但火龙果产业却受到气候、市场环境等因素制约.提出越南火龙果产业国际合作发展对策如下:开发国际火龙果种质资源共享系统平台,助力品种研判;成立国际火龙果科研联盟,构建大型跨国科研项目;以市场为导向进行新品种选育,丰富火龙果品种资源;重新规划传统果园,打造休闲综合体,形成多元化收益体系.

本文对农业农村部南宁火龙果种质资源圃从我国广西、广东、海南、福建、上海、云南、贵州、台湾等省(区)以及越南和以色列等地收集引进的359份资源进行鉴定分析,将相关资源数据通过建立数据库形式进行共享应用.火龙果种质资源数据库基于B/S三层网络架构,采用ASP.NET和SQL Server2008数据库技术和领域驱动模式进行开发.系统录入各火龙果种质资源相关数据,包括基本信息、植物学性状、农艺性状、果实品质等,系统具有数据可视化管理、检索、图片管理等功能.数据库的构建与应用,旨在实现火龙果种质资源信息化、规范化、标准化管理,提升火龙果种质资源信息共享利用率,为火龙果育种和产业发展提供助力.

以龙眼成熟叶片为材料,克隆龙眼MYB-related基因家族TRF2-like基因,命名为DlTRF2-like,并对其进行生物信息学和表达模式分析.DlTRF2-like基因属于MYB-related家族的TRF-like亚家族,ORF长度是909 bp,编码含有302个氨基酸残基的蛋白,预测该基因定位于细胞核,同源基因进化分析表明龙眼DlTRF2-like与阿月浑子PvTRF2-like亲缘关系最近.利用实时荧光定量PCR检测DlTRF2-like基因在'四季蜜'龙眼不同组织及乙烯利和多效唑处理后不同时间的相对表达量.结果表明:DlTRF2-like在龙眼不同组织中均有表达,在花芽中表达量最高;乙烯利和多效唑处理后,DlTRF2-like基因的表达量明显高于对照,推测DlTRF2-like响应乙烯利和多效唑信号促进龙眼成花.

以龙眼成熟叶片为材料,通过转录组测序及生物信息学分析得到龙眼ZAT10基因全长序列,命名为DlZAT10(GenBank登陆号:MT117769),进一步设计特异引物对其开放阅读框(ORF)全长序列进行克隆和生物信息学分析.DlZAT10基因属于C2H2锌指蛋白家族的C1-2i亚家族,ORF长度为738 bp,编码245个氨基酸,无内含子,有2个典型的C2H2结合位点.该蛋白属于非跨膜亲水蛋白,预测定位于细胞核,存在40个氨基酸磷酸化位点.其二级结构主要由无规则卷曲,以及α-螺旋和β-折叠构成,二级结构与三级结构预测结果高度一致.同源基因进化树分析表明,该基因与柑橘和阿月浑子亲缘关系最近.同时成功构建了植物超表达载体PBI121-DlZAT10,为DlZAT10基因功能的深入研究奠定了基础.

[目的]探究禾荔特晚熟焦核突变体GLL-1的全基因组变异情况,为调控荔枝果实成熟期、解析焦核发生分子机制及选育焦核品种提供理论支持.[方法]通过荔枝种质资源普查发现1个禾荔特晚熟焦核突变体GLL-1,对禾荔和GLL-1开展全基因组重测序(测序深度50×),对比分析GLL-1全基因组变异情况.[结果]与禾荔相比,GLL-1果实明显较大,品质优良,特晚熟,种子变为焦核,可食率明显提高.从GLL-1基因组获得320858674个高质量的Clean reads,定位到荔枝参考基因组的高质量Clean reads数占比为96.07％,正确识别率大于Q20的碱基占比为96.48％,正确识别率大于Q30的碱基占比为91.38％,基因组GC含量为35.28％,覆盖度(大于1×的碱基占比)为97.62％.检测到9306084个单核苷酸多态性(SNP)位点和759887个小片段插入和缺失(Indel)位点,共导致12621个基因发生变异,其中发生非同义SNP突变的基因8451个,发生Indel的基因4170个.许多与花色素苷生物合成相关的MYB、bHLH、WD40转录因子家族基因及参与ABA信号转导的重要家族基因(bZIP、WRKY、MAPK及PPR)均发生突变.[结论]MYB、bHLH、WD40、bZIP、WRKY、MAPK及PPR等家族基因的突变可能是导致GLL-1果实特晚熟及焦核发生的一个主要原因,推测其在调控荔枝果实发育和焦核发生中发挥关键作用.

Litchi (Litchi chinensis Sonn.) is an important subtropical fruit crop with high economic and nutritional values. Fruit coloration is a sign of litchi fruit ripening and an important external quality traits. Two continuous generations of mutants, named MS1 and MS2, originally derived from cultivar 'Heli', exhibited the distinctive characteristic of late maturation of 20 d, with observable delays in coloration. The present study aimed to understand the mechanism underlying maturation difference between 'Heli' and its two mutants. An RNA-seq analysis revealed 6,145 differentially expressed genes, mostly identified at the color-breaking stage. The maximum expression levels of some genes involved in anthocyanin biosynthesis and chlorophyll degradation were delayed in the pericarp of the mutants compared with in the original cultivar. Generally, they peaked at earlier stages (S2/S3) in 'Heli', compared with later stages (S4/S5) in mutants. Moreover, some hormonal signal receptors, especially those involved in abscisic and ethylene signaling pathways, were also differentially expressed between the original cultivar and the mutant. Transcription factors, including MYB, bHLH, bZIP, and WRKY, correlated with anthocyanin biosynthesis, chlorophyll degradation and abscisic acid signal pathways were identified. The late pigmentation in mutants was related to the fruit ripening program, a complex and comprehensive process. Additionally, we identified novel candidate genes that are involved in the regulation of litchi fruit pigmentation of and gained significant insights into the process of litchi fruit ripening.

从广东、广西引进国内近年选育的18个荔枝新品种,在广西灵山县“灵山香荔”大树上高接换种进行集中引种对比试验.参照《荔枝种质资源描述规范和数据标准》制订果实性状评价标准,依据果皮颜色等10个果实性状的重要程度分别赋予不同分值,总分100分.于2018-2020年连续3年分别对引进品种果实性状测评评分,按3年平均得分对果实综合性状进行排名筛选.结果 表明,糯桂、仙进奉、红绣球、红珍珠排在前四位,在当地荔枝主产区品种结构调整可以优先考虑选用.有些品种虽然综合评分不高,但是具有某个特异性状或某些特殊优良性状,如马贵荔单果质量最大,是平均值的166％,穗大、特迟熟,果肉内膜褐色少;范焦1号、井岗红糯、岭丰糯和凤山红灯笼的焦核率均为90％以上且稳定,这些性状在种质资源创新及育种利用中很有价值.