简述了国内外荔枝种质资源情况,介绍了中国荔枝种质资源的考察、收集、保存情况,综述了近些年荔枝种质资源表型评价、遗传多样性研究、核心种质库的构建等进展,并提出了改进荔枝种质资源工作的建议.

"宝石1号"龙眼是福建省农业科学院果树研究所杂交选育的龙眼新品种,具有丰产稳产、可食率高、果肉爽脆、化渣、风味甜、含糖量高等优点,2017年引种到海南省儋州市.在海南省儋州市,"宝石1号"龙眼生长旺盛,能够快速形成丰产树冠,盛花期在3月下旬,果实成熟期7月中旬,平均单果质量13.8～14.2 g,可溶性固形物含量为17.9％～19.6％,可食率72.9％～75.7％,优于目前儋州主栽品种"石硖".采用反季节催花栽培,"宝石1号"龙眼的现花期比"石硖"早,成花率比"石硖"高.

为了探究叶面喷施混合钙镁肥克服'三月红'荔枝果皮"滞绿"现象的生理生化机制,以'三月红'荔枝的成年单株为试验材料,以叶面喷施混合钙镁肥为处理,以喷清水为对照(CK),观测其果皮色素、内源激素含量以及相关酶的活性.结果表明,处理与CK的色调角(h值)、叶绿素和生长素(IAA)等含量总体呈下降趋势;糖酸比和花色素苷、乙烯(Eth)、脱落酸(ABA)、赤霉素(GA3)等含量及类黄酮糖基转移酶(UFGT)、叶绿素单加氧酶(PaO)、叶绿素酶(Chlase)等活性总体呈上升趋势;处理果实的h值在3月29日、4月5日和4月12日显著低于CK;花色素苷含量在4月5日至4月12日之间则显著高于CK;处理的叶绿素含量在4月5日和4月12日显著低于CK;处理的糖酸比在4月5日后显著高于CK;处理的Eth含量在3月29日及4月8日、15日显著高于CK;处理的果皮ABA含量在4月5日后显著高于CK;处理的IAA含量在4月1日显著低于CK,4月12日显著高于CK;处理的UFGT活性在3月29日显著低于CK,4月8、12日显著高于CK;处理的PaO活性在4月1日、8日、12日显著高于CK;UFGT活性与ABA、Eth含量极显著正相关;PaO活性与Eth含量极显著正相关;花色素苷含量与ABA、Eth含量和UFGT活性极显著正相关;叶绿素含量与Eth含量和UFGT、PaO活性分别极显著负相关,与ABA显著负相关;处理与CK的GA3含量、Chlase活性全程同期间均无显著差异.可见,喷施混合钙镁肥处理可促进着色而克服果皮"滞绿"现象,主要是通过提高Eth与ABA等含量、进而提高UFGT和PaO活性等促进花色素苷的合成和叶绿素降解,使得果皮在果肉糖酸比最高时提前着色,成功克服了果皮"滞绿"现象.

海南反季节龙眼采前落果普遍发生,严重制约了反季节龙眼产业的发展.而果柄分离力可以反映果实离层活动的状况,成为果实脱落进程的重要指标,但未见在龙眼上使用的报道.本研究以DS2-1000 gf和DS2-5000 gf型推拉力仪检测果柄分离力,并分析果实脱落过程中各项生理特性参数,旨在弄清龙眼果实脱落过程中果柄分离力与果实碳水化合物、呼吸速率和离层细胞壁代谢酶活性的关系.数据表明反季节龙眼果实脱落过程中,果柄分离力的变化范围为0～3000 gf,且果柄分离力低于1000 gf会导致果实呈现脱落趋势;落果率与果柄分离力呈现显著负相关性(r=-0.984,P=0.000);果实总糖和淀粉含量与果柄分离力呈现显著正相关性,相关系数分别为0.942(P=0.005)和0.952(P=0.003);果柄呼吸耗氧速率与果柄分离力呈负相关性(r=-0.807,P=0.099);果柄离层纤维素酶和β-甘露聚糖酶活性也与果柄分离力呈显著分负相关性,相关系数分别为-0.936(P=0.019)和-0.954(P=0.002).结果 表明反季节龙眼果实脱落进程可用果柄分离力的变化体现,果实脱落进程伴随着果柄分离力的不断降低,与果柄细胞壁降解酶活性的增加呈线性关系;脱落的发生与碳水化合物含量关系密切,而高的果实呼吸消耗,可能加快果实脱落进程.

为了解荔枝叶片白化变异体遗传特点,本研究以白化变异体比例较高的'玉谭蜜荔'白化变异体苗与正常苗为试验材料,测定叶片叶绿素含量,并观测叶绿体结构差异,最后通过高通量测序技术对苗期叶片进行转录组测序分析.结果 表明:'玉谭蜜荔'种子实生苗中白化变异体的比例约为8.59％;白化苗叶片色素含量极低,仅为正常苗的0.519％;叶绿体的结构松散,基粒片层结构较少或缺失.对高通量测序数据进行组装和注释,共获得Unigene 42 782条,平均长度987 bp,比对到Nr、KOG、KEGG、Swiss-prot四大数据库中,超过64％的Unigene序列获得注释,差异分析表明在细胞色素合成、光系统亚基合成蛋白、采光复合物a/b结合蛋白相关序列表达显著下调.本研究为该变异体的基因定位鉴定提供了一定的遗传基因注释信息.

研究了正造及反季节龙眼树体叶片及顶芽中内源激素IAA、GA、ABA、iPA、ZR在花芽分化过程中的变化.结果表明,花芽分化过程中叶片及顶芽ABA含量最高,IAA次之,ZR、iPA及GA含量极低.氯酸钾处理可导致叶片及顶芽iPA含量迅速升高;叶片GA含量远高于顶芽,而ABA以顶芽中富集量最大;ZR以顶芽含量较高;虽然IAA在叶片和顶芽都有较高水平,但变化幅度不大.综合各激素变化情况认为,花芽分化过程中iPA、GA、ABA含量变化幅度最大,且ABA在花芽分化的发生部位顶芽富集说明ABA在龙眼花芽分化过程中起更重要的作用.

采用水培试验,分析了3种浓度6-BA对妃子笑荔枝叶片光合参数和可溶性糖含量的影响.结果表明,6-BA对妃子笑叶片光合荧光参数Fv/Fm和PIabs有影响,在低浓度水平下(5 mg/L),喷施6-BA可以提高叶绿体光系统II的光合潜能和光合效率;同时,可以较长时间地保持叶片可溶性糖含量在较高水平.

一氧化氮(NO)作为一种胁迫后的重要信号分子,在植物生长发育的许多过程中具有重要的调节作用.越来越多的研究证据表明,NO在植物花发育过程中具有重要作用,然而迄今尚鲜见关于NO调控果树成花发育方面的系统报道.该研究介绍了植物NO合成途径的最新研究进展,综述了NO在草本及木本植物中开花转变存在的差异,以期为植物内源NO对木本果树花芽分化的调节研究提供理论参考.

Quality analysis was performed to major cultivars,‘Hongxin pomelo’ and ‘Wuzi pomelo’ with uniform maturity.Total soluble solid (TSS),titratable acid,vitamin C,juice yield,edible rate,single-fruit weight and pesticide residues of the 2 cultivars were detected.The results showed that:the TSS contents of ‘Hongxin pomelo’ and ‘Wuzi pomelo’ were in the range of 8％-12％,the vitamin C contents were in the range of 0.3-0.6 g/L,the juice yields were in the range of 56％-68％,the edible rates were in the range of 52％-68％,and the single-fruit weights were in the range of 1-2.5 kg.The titratable acid content was higher in ‘Hongxin pomelo’ than in ‘Wuzi pomelo’.Only Dursban and imidacloprid were detected at low concentrations in pericarp,and the residues of the 3 pesticides were all lower than their detection limits.Therefore,honey pomelo produced in Hainan all could be ate safely.

为阐明H2O2和NO对龙眼成花及AP1基因表达的影响,选用9年生反季节储良龙眼结合H2O2和NO促进剂及信号阻断剂喷施,分析成花及AP1基因表达量的动态变化.结果表明,反季节龙眼AP1基因在成花过程中表达量上升,而SNP和MV处理均不同程度上调了侧花原基形成时顶芽和叶片中AP1基因的表达,尤以SNP处理效果最为显著;DMTU处理显著抑制了侧花原基形成时顶芽和叶片中AP1基因的表达,L-NNA处理对侧花原基形成时叶片AP1基因表达有轻微的抑制作用,对顶芽AP1基因表达影响不大.结合龙眼成花情况,推断加强NO、H2O2信号有助于促进龙眼成花,而阻断H2O2信号将抑制龙眼成花.

[目的]研究海南龙眼的鲜食品质特性.[方法]选择成熟度一致的海南主栽品种正造及反季节龙眼进行品质分析,分别检测其糖含量、维生素C含量、可食率、TSS、单果重、穗果重、农药残留,[结果]正造龙眼与反季节龙眼品质无差别,且反季节龙眼TSS略高于正造.海南两个主栽品种‘石硖’和‘储良’之间的食用品质有明显的差别:‘储良’单果重及可食率略高于石硖,穗果重相近;‘石硖’维生素C及TSS含量高于‘储良’;‘石硖’单糖含量显著高于‘储良’,而蔗糖含量低于‘储良’.仅在果皮中检测出低浓度的氯氰菊酯、除虫脲残留,果肉中9种农药残留均低于检出限.[结论]在海南境内生产的龙眼均可安全食用.

概述了‘新球蜜荔’的选育过程、品种性状、区域试验及栽培技术要点,于2013年通过海南省作物品种审定委员会认定. ‘新球蜜荔’属于中晚熟品种,果实于6月上中旬成熟,产量与目前海南主栽的‘妃子笑’相近;成熟时果皮黄绿色,果肉米白、汁多,有蜂蜜香味;平均单果重32.56 g,可食率71.39％,可溶性固形物含量(wTSS)18.25％.

"玉谭蜜荔"是由海南原生荔枝资源中选育出的优质高产品种,于2013年通过海南省作物品种审定委员会认定。果实平均单果质量20.60g,可食率74.50%,穗果率高,可达21以上,6年生单株产量达到30kg。果实成熟时鲜红至紫红色,有浓郁蜂蜜香味。在海南,玉谭蜜荔6月上旬成熟。

为阐明H2O2和NO对龙眼成花及FT基因表达的影响,选用9年生‘石硖’反季节龙眼,结合H2O2和NO促进剂及信号阻断剂喷施,分析龙眼成花及FT基因表达量的动态变化.结果表明:反季节龙眼FT基因表达量在成花过程中上升,且叶片中FT基因表达高峰时间早于顶芽,而SNP和MV均不同程度上调了FT基因的表达;DMTU和L-NNA有效地抑制了顶芽中FT基因的表达,但对花芽分化后期的叶片中FT基因表达抑制不明显.结合龙眼成花情况,推断H2O2和NO信号在促进龙眼成花方面具有重要作用.

以储良龙眼为试材,通过分析低温诱导、氧化胁迫、自然低温+药剂处理龙眼成化过程中氧化损伤各指标变化,研究龙眼成花和氧化胁迫之间的相关性.结果表明,氧化胁迫有利于龙眼成花.对顶芽和叶片活性氧、抗坏血酸和丙二醛(MDA)含量的检测结果也表明,氧化胁迫诱导龙眼成花的同时,也导致了龙眼树各组织活性氧的累积,且抗坏血酸抑制龙眼成花,MDA促进龙眼成花.因此认为活性氧与龙眼成花呈正相关.

In this study, a total of 11 hybridization combinations were created by artificial or controlled pollina-tion methods with six litchi varieties as parents, i.e., Ziniangxi, Wuheli, Baitangying, Feizixiao, Sanyuehong and Xinqiumili, from 2011 to 2014. 1 666 true hybrids from 2 317 F1 seedlings were identified using five pairs of SSR markers and three pairs of InDel markers. The results showed that:the true hybrid rates of the 11 hybridization combinations were different, with the average rate of true hybrids at 71.90%. Some absent or new SSR and InDel loci in phenotypes of F1 seedlings was appeared. Five homozygous makers were identified which could be used to identify the cross combinations of Ziniangxi ×Wuheli, Wuheli ×Ziniangxi, Ziniangxi ×Feizixiao, Ziniangxi ×San-yuehong, Xinqiumili×Wuheli, Wuheli×Xinqiumili Baitangying×Wuheli and Baitangying×Sanyuehong. The results demons-trated that no significant difference of the true hybridizaiotn rate between artificial pollination and controlled pollination method.

After flower induction, with the neighbored body conditions, some longan trees can successfully blossom and yield, while others can only sprout leaf buds. In order to research the original reasons which caused the differences, we took off-season flowering trees and non-flowering ones as contrastive materials after flower forcing, and studied the changes of carbon content in the climax leaves, tender leaves, climax shoots, tender shoots and terminal buds of longan tree. The results showed that carbon played a major role in flowering process. Moreover, these trees could easily flower when the carbon content in climax leaf reached 50.93 mg/g, but when the carbon content was below 37.40 mg/g in climax leaf, the longan trees were difficult to flower. At the same time, the maturity of tender leaf also had a great influence upon flowering. In comparison, a mature leaf contained more carbon content than that of a tender one, and was easier to flower.This can be used as a new judgment standard of flower induction in off-season longan trees.

The abscission of fruit due to the degradation of intercellular substance in abscission zone,while the degradation of intercellular substance depends hydrolase,which made hydrolase become one of the focused researches in recent years.In this review,the research status of hydrolase was summarized,including its biochemical characteristics,cloning and expression,and degradation of intercellular substance effect.Besides,the future directions of hydrolase were also pointed out,with a hope to guide the further study of hydrolases during fruit abscission process and the development and utilization of related products.

为了确定海南中西部妃子笑荔枝的营养诊断时间及荔枝正常生长所需营养元素的最适范围.以海南中西部具有代表性的妃子笑荔枝种植园为试验地,对海南中西部地区妃子笑荔枝叶片9种元素含量进行测定分析,并运用标准值法对妃子笑荔枝进行营养诊断.结果表明:海南中西部妃子笑荔枝叶片元素含量在不同的生育期差别较大,初步确定盛花期为海南妃子笑荔枝营养诊断的最佳时期;妃子笑叶片盛花期适宜的元素含量范围为N 16.0～19.0 g/kg、P 0.9～1.2 g/kg、K 7.0～10.0 g/kg、Ca 5.0～11.0 g/kg、Mg 1.5～3.0 g/kg、Fe 60.0～140.0 mg/kg、Cu4.0～9.00 mg/kg、Zn 15.0～64.00 mg/kg、B 3.00～18.00 mg/kg;各元素含量适宜比例为N∶P∶K∶Ca∶Mg=1.00∶0.06∶0.51:0.46:0.13; Fe∶Cu:Zn:B=1.00:0.07:0.40:0.11.

To study whether a correlation exists between longan flower and oxidative defense, low temperature induction, oxidative stress, natural low temperature combined medicament spraying in‘shixia’ longan buds and leaves were tested. The results showed that oxidative stress and low temperature combined NO/H2O2 generator treatment displayed significantly effect to longan early flower. NO promoter could inhibit POD activity of longan buds in the late flower period, and H2O2 scavenger treatment had led to a POD and SOD activity increased sharply. Al the results showed that longan flower signals were positive regulated by oxidative stress, and oxidative defense system negative regulation of longan flowers.