麦芽糖、NAA及ABA对华北落叶松体细胞胚成熟及生根的影响

研究了麦芽糖、NAA、ABA对华北落叶松体细胞胚发生及体细胞胚根发生和再生完整植株的影响。结果表明 :在胚性愈伤组织继代、增殖过程中 ,以 0 5mg·L- 1 的NAA代替 2 ,4 -D后 ,有利于体细胞胚的成熟和根发生。在ABA 16mg·L- 1 时 ,产生的华北落叶松体细胞胚 ,能够再生良好植株 ,ABA大于 2 0mg·L- 1 时对体细胞胚根的发育不利。在含 3%麦芽糖、4 %PEG4 0 0 0活性炭 1g·L- 1 的成熟培养基上 ,华北落叶松每克愈伤组织子叶胚达 10 6 7个 ,生根率达 5 7 89% ;显著地提高了成熟体细胞胚及其根的质量。     

外源激素对日本落叶松体细胞胚发生不同阶段的影响

【目的】探究外源激素对日本落叶松体细胞胚发生不同培养阶段的影响,优化日本落叶松的体细胞胚发生条件并提高体细胞胚的质量,为研究外源激素调控落叶松体细胞胚发生的生理机制提供数据支持,为落叶松的规模化繁育和遗传改良奠定基础。【方法】首先确定生长曲线的延迟期、对数期和平台期,然后根据生长曲线,采用正交设计研究胚性胚柄团在2,4-D 0.15、0.30、0.50 mg·L-1、6-BA 0、0.15、0.30 mg·L-1和ABA 0、0.50、1.00 mg·L-1浓度下培养7天、14天、21天的鲜质量增长情况和14天的体胚发生能力,采用析因设计研究悬浮细胞在2,4-D 0.15、0.30、0.50 mg·L-1和6-BA 0、0.15、0.30 mg·L-1浓度下培养7天、14天、21天的细胞鲜质量增长情况和14天的体胚发生能力,结合鲜质量增长和体胚发生能力2种结果确定胚性胚柄团增殖和悬浮细胞生长的最佳激素浓度。最后,以不含GA3、IAA的体细胞胚诱导培养基为对照,分别研究了GA3和IAA 0、10、20、30、40 mg·L-1对体细胞胚发生的影响。【结果】7、14、21天分别处于日本落叶松胚性胚柄团增殖和悬浮细胞生长的延迟期、对数期和平台期。在胚性愈伤组织增殖阶段,2,4-D、6-BA、ABA对胚性胚柄团增殖和体胚发生能力的影响显著(P0.05),最佳的激素浓度是2,4-D 0.15 mg·L-1+ABA0.50 mg·L-1;在悬浮培养阶段,2,4-D、6-BA组合对悬浮细胞生长和体胚发生能力的影响显著(P0.05),最佳激素浓度是2,4-D 0.15 mg·L-1+6-BA 0.15 mg·L-1; GA3、IAA对成熟子叶胚的数量的影响均显著(P0.05),10～20 mg·L-1GA3或IAA时成熟子叶胚数量显著升高,而更高的GA3或IAA浓度将会抑制体胚发生。【结论】外源激素可有效调控日本落叶松的体细胞胚发生,适宜增殖阶段胚性胚柄团增殖和体胚发生能力保持的激素组合为2,4-D 0.15 mg·L-1+ABA 0.50 mg·L-1,适宜悬浮培养阶段细胞生长和体胚发生能力保持的激素组合为2,4-D 0.15 mg·L-1+6-BA 0.15 mg·L-1,添加GA3或IAA 10～20 mg·L-1可以显著提高成熟子叶胚的数量。     

miR396在落叶松体细胞胚胎中的功能研究

[目的]探讨miR396在落叶松体细胞胚胎发生中的功能.以期该研究能为解决体胚发育中子叶畸形胚与生根率低的问题提供新的视角,同时也为进一步揭示体胚发育的分子调控网络做基础铺垫.[方法]构建pre-miR396超表达载体,通过农杆菌介导侵染,将pre-miR396转入落叶松胚性细胞中,筛选稳定抗性细胞系.在DNA与RNA水平上,对抗性细胞系进行的鉴定、检测,同时统计比对其与野生细胞系间发芽率、叶片数目以及生根率的差异.[结果]在抗性细胞系基因组中,扩增出HTP与miR396的特异性片段,且无农杆菌Virg基因片段.RNA表达水平上,抗性系pre-miR396与miR396表达皆增加,而靶基因LaGRFs的表达量下调.统计表明抗性系胚的发芽率、生根率、叶片数目畸形率分别为70.60%、0.60%、37%,而野生型分别为92.50%、10.55%、4%,抗性系胚的发芽率、生根率显著降低(Sig.=0.000),叶片数目畸形率显著增加(Sig.=0.000).[结论]miR396在落叶松体细胞胚胎发生过程中,可能通过负调节靶基因LaGRFs的表达或者通过LaGRFs影响与它相互作用的基因,参与体胚子叶原基细胞代谢,从而影响了子叶与叶片的发育;通过负调节LaGRFs或者其它与根部发育相关的靶基因,影响了根端分生区细胞的活动,参与调控根的发育.     

水曲柳不同外植体胚性愈伤组织诱导及植株再生

本研究以水曲柳不同外植体(无菌苗叶片和下胚轴、未成熟合子胚、成熟和未成熟合子胚子叶)为材料，在胚性愈伤组织诱导、胚性愈伤组织增殖、体胚形成、体胚萌发生根培养基上诱导分化。结果表明，附加了5.0 mg·L^-1 NAA和2.0 mg·L^-1 6-BA的激素配比的MS培养基，为诱导水曲柳胚性愈伤组织最适培养基；在5种不同的外植体中，成熟和未成熟合子胚子叶更适合作为诱导胚性愈伤组织的外植体；在诱导胚性愈伤组织中，成熟合子胚子叶诱导率为11.7%,未成熟合子胚子叶诱导率为9.7%;胚性愈伤组织在继代培养过程中，WPM为最佳基础培养基，附加0.1 mg·L^-1 6-BA和0.15 mg·L^-1 2,4-D的激素配比，胚性愈伤组织的增殖系数可达到1.54。在体胚成熟过程中，MS培养基内添加1.0 mg·L^-1 ABA时，体胚的诱导率最高，达到55%。在生根萌发的WPM基础培养基中附加1.0 mg·L^-1 IBA和1.0 mg·L^-1 IAA的激素配...     

落叶松体细胞胚发生研究进展

以体细胞胚发生的发展阶段为线索，对落叶松胚性培养物的诱导、胚性愈伤组织的保持和增殖、体胚成熟、体胚的萌发进行了全面的论述。     

栓皮栎体胚的增殖、成熟和萌发

以栓皮栎实生苗叶片为外植体诱导体细胞胚胎发生,调查碳水化合物、渗透剂和植物生长调节剂对体胚增殖、成熟和萌发的影响,建立体胚增殖、成熟和萌发的培养基方案.叶片外植体在附加1.0 mg·L-1NAA和0.5mg·L-1BA的起始培养基上诱导形成前胚性团块.这些胚性团块在增殖培养基上培养6周,在附加1 mg·L-1BA、0.25 mg·L-1NAA和3%蔗糖的MS培养基上增殖效果最好.将单个体胚转接到成熟培养基上进行培养,蔗糖浓度对栓皮栎体胚成熟以及后续的萌发有显著影响.成熟培养基中附加5%的蔗糖,体胚成熟率和萌发率分别达到63.5%和33.8%.虽然在成熟培养基中附加ABA有利于体胚成熟,但对体胚的进一步萌发没有促进作用.为了提高萌发率,成熟体胚在附加植物生长调节剂的萌发培养基上进行培养,以及进行预冷处理.成熟体胚4℃冷处理没有促进胚根和上胚轴的发育萌发.在附加0.5 mg·L-1BA和0.25 mg·L-1 IBA的1/2 MS萌发培养基上,体胚萌发率达到65.9%,再生植株转化率达到9.4%.     

樟树胚萌发早期影响因素及植株再生

【目的】植物体细胞胚胎发生和植株再生受多重因素影响。为了完善樟树体细胞胚胎发生培养技术,提高其遗传转化效率,满足樟树用材的需要。【方法】本研究以樟树未成熟种子为试材,探讨了预处理、不同采种时间、活性炭、肌醇及激素浓度对樟树胚萌发早期的影响,并对不同种源樟树胚性愈伤组织诱导体细胞胚胎发生、分化、生根等进行研究。【结果】预处理对樟树幼胚萌发无显著性影响;不同的采种时间对胚萌发率和平均出芽数影响很大;随着活性炭浓度的升高,胚萌发率呈现先升高后下降的趋势;肌醇浓度对樟树幼胚萌发率和平均出芽数均无显著性影响;对6-BA、NAA、IBA和链霉素进行正交设计试验,其影响的主次顺序为:6-BA> NAA>链霉素> IBA;长沙和郴州种源樟树胚性愈伤组织诱导率最高,达66.67%,但生长情况最好的是长沙和岳阳种源胚性愈伤组织;岳阳、郴州、醴陵、长沙、怀化、娄底愈伤组织诱导体胚发生最大诱导率分别为56.41%、42.31%、48.96%、64.71%、63.25%、56.31%;各种源樟树生根率良好,长沙种源有最高生根率89.25%,郴州和醴陵种源樟树最佳生根激素配比为1 mg/L IBA+0.1 mg/L IAA,其余种源生根最适激素均为1 mg/L IBA+0.1 mg/LNAA。【结论】浸泡处理不利于幼胚后期生长发育;附加150 mg/L的活性炭,培养基褐化率较低;6-BA对幼胚早期萌发占主导作用;实验时选择7月未成熟合子胚的长沙种源樟树最佳。     

花曲柳体胚发生和植株再生

以花曲柳合子胚的单片子叶为外植体成功诱导出体胚并获得再生植株。未成熟合子胚的子叶在添加400mg·L-1水解酪蛋白、0.25mg·L-16-BA、1.5mg·L-1NAA、70g.L-1蔗糖和6g·L-1琼脂的MS1/2培养基上可以成功诱导产生体胚,诱导率达到34.7%,每个外植体上体胚数量为2～9个。成熟合子胚的子叶在添加0.25mg·L-16-BA、2mg·L-1NAA的MS1/2培养基(其他成分同上)上可以成功诱导产生体胚,诱导率为10.0%。体胚在MS1/2培养基上经过成熟培养后可以正常萌发,萌发率87.6%。萌发的体胚植株在MS1/2+0.01mg·L-1NAA培养基上生长较好,具备实生幼苗的外观特征。经炼苗后的体胚苗移植到栽培基质(草炭土:蛭石:珍珠岩体积比为5:4:1)中可以正常生长,成活率为75.0%。     

蒙古沙冬青子叶节诱导培养再生植株的研究

[目的]建立蒙古沙冬青子叶节丛生芽再生体系。[方法]以蒙古沙冬青子叶节为外植体,研究种子萌发培养基中6-BA浓度、子叶节萌发天数、丛生芽诱导的基本培养基及6-BA浓度对丛生芽诱导的影响和外源激素对丛生芽伸长及生根的影响。[结果]表明:(1)添加6-BA的萌发培养基与不添加的相比能够显著促进子叶节的生长及子叶节丛生芽的诱导,且6-BA浓度在2.0 mg·L-1时,诱导率最高可达73.3%,平均芽数2.26个;(2)种子萌发天数对子叶节丛生芽的诱导有显著影响,萌发7 d的子叶节丛生芽诱导率最高,诱导率为74.7%,但与萌发9、11 d的子叶节丛生芽诱导率差异不显著;(3)MS和B5培养基对丛生芽诱导的影响差异不显著,但B5抑制褐化的效果显著好于MS;(4)采用1.0 mg·L-16-BA+0.3 mg·L-1IAA激素组合有利于丛生芽伸长,伸长率为60.5%;(5)不同浓度生长素组合均能促进丛生芽幼苗生根,1.0 mg·L-1IBA生根率最大,生根数最多。[结论]最佳蒙古沙冬青子叶节丛生芽再生体系为:以在MS+2.0 mg·L-16-BA培养基中黑暗培养7 11 d的幼苗子叶节为外植体,在B5+1.0mg·L-16-BA培养基中诱导丛生芽,待丛生芽长约0.3 0.5 cm后,转入B5+1.0 mg·L-16-BA+0.3 mg·L-1IAA培养基中进行伸长培养,当丛生芽伸长至2 3 cm时,单株切下转入1/2 B5+1.0 mg·L-1IBA培养基中生根,该体系与愈伤组织培养相比能缩短培养时间,改善褐化严重、玻璃化等问题,可为蒙古沙冬青的扩繁及进一步开展遗传转化奠定基础。     

抗松材线虫病赤松体细胞胚的发育和成熟萌发

【目的】研究脱落酸、PEG、肌醇、碳源、凝固剂及培养方式等对抗松材线虫病赤松体细胞胚发育及成熟萌发的影响。【方法】通过对抗松材线虫病赤松种质资源库的调查与分析,选用诱导和增殖状态良好的抗松材线虫病赤松无性系22#-1和13#-1为供试材料,通过不同培养条件的对比试验,筛选出最优的抗病赤松体细胞胚发育及成熟萌发条件。采用SPSS17.0等软件对体细胞胚进行统计分析。【结果】添加15 mg·L~(-1)ABA和140 g·L~(-1)PEG8000的LP培养基上,正常体细胞胚数达到171个·g~(-1),高于其他处理;在渗透剂方面,肌醇的浓度为8.0g·L~(-1)时,抗病赤松的正常体细胞胚数最多,达到179个·g~(-1),胚性愈伤组织直接放置于添加了肌醇的成熟培养基中,没有在中间过渡培养基中培养,因此可以缩短2~3周培养时间,在8周前后就形成了成熟的子叶胚;在碳源方面,添加60 g·L~(-1)麦芽糖的LP培养基上,正常的体细胞胚数达到235个·g~(-1),高于其他处理;在凝固剂方面,植物凝胶浓度为3.0 g·L~(-1)时,培养基凝固,软硬适中,产生的子叶胚生长良好,而培养基中添加了聚乙二醇(PEG),凝固剂琼脂从6.0 g·L~(-1)添加至12.0 g·L~(-1)时,培养基均不能凝固,愈伤组织无法生长,也无子叶胚形成;在培养方式方面,采用液-固增殖-固成熟方式培养时,胚性愈伤组织经11~12周发育为成熟体细胞胚,其中22#-1的正常体细胞胚数最多达到239个·g~(-1),高于其他处理;在体细胞胚萌发培养基上产生的体细胞胚的萌发率和植株转化率分别为67.2%和46.5%,再生植株移栽3个月后成活率为32.7%。【结论】将抗松材线虫病赤松胚性愈伤组织置于15.0 mg·L~(-1)ABA、140 g·L~(-1)PEG8000、8.0 g·L~(-1)肌醇、60 g·L~(-1)麦芽糖、3.0 g·L~(-1)植物凝胶的LP培养基上,以液-固增殖-固成熟培养方式培养,成功获得了正常的体细胞胚和再生植株,同时可缩短2~3周培养时间,加快抗松材线虫病赤松体细胞胚胎发生的进程。研究结果可为抗病赤松的大规模繁殖和工厂化生产提供技术支持。     

<Emphasis Type="Italic">Ophiostoma</Emphasis> species associated with bark beetles infesting three <Emphasis Type="Italic">Abies</Emphasis> species in Nikko,Japan

Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied.     

Improving the evaluation of multiple-dowel-type connection strength

Our study focuses on predicting the ultimate short-term load carrying capacity of timber-to-timber connections with dowel-type fasteners. The wide range of possible configurations in practice makes the resolution of these values by tests unrealistic. Moreover, different current regulations do not consider some specific failure mechanisms. In many countries, the reduction of resistance involved by this phenomenon is taken into account by considering an effective number of dowels (n_ef) smaller than the actual number of dowels (n) in the connection. However, these different regulations disagree on the values of n_ef and on other points (spacing, partial coefficient of security, formulas). These discrepancies in design rules invite the fundamental research on this topic and, therefore, new methods are sought in order to estimate the load carrying capacities of the connections. In the light of these, our approach consists of predicting the load carrying capacity with the neural network numerical tool. The results obtained by this analysis tool are satisfactory, although the model remains complex. Subsequently, we focus on the simplification of this numerical model with classical regression techniques in order to implement it in a design code.     

Parasitic Ichneumonoidea on the horse chestnut leaf miner, Cameraria ohridella (Lepidoptera: Gracillariidae) in Slovakia

Parasitic Hymenoptera from the suprafamily Ichneumonoidea attacking the horse chestnut leafminer Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae) were studied in southwest Slovakia during 2000 and 2001. The search for such species resulted in the determination of eight ichneumonid species, Gelis agilis (Fabricius), Itoplectis alternans (Gravenhorst), I. clavicornis (Thompson), I. maculator (Fabricius), Scambus annulatus (Kiss), S. brevicornis (Gravenhorst), Zatypota percontatoria (Müller), Adelognathus sp. and a braconid Colastes braconius Haliday. The most abundant species was S. annulatus. All these species recorded are polyphagous and often facultative hyperparasitoids, except C. braconius, which departs from this norm in not being hyperparasitic. The presence of more diversified native parasitoids and hyperparasitoids from the Ichneumonoidea predicate a slow successive adaptation of the parasitoid fauna to the invasive host, Cameraria ohridella.     

Insecticidal activity of certain medicinal plants

The methanol extracts of eight species of medicinal plants were tested for insecticidal activity in third instar larvae of Egyptian cottonworm (Spodoptera littoralis). All extracts showed a certain degree of larval toxicity. The extracts of Ocimum basilicum, Origanum majorana and Salvia officinalis appeared to be highly toxic. The extracts significantly affected the growth indexes [relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD)].     

A new norlignan from Taxodium ascendens

A new norlignan, (2R,3R,4S,5S)-2,4-bis(4-hydroxyphenyl)-3,5-dihydroxy-tetrahydropyran (1), together with 9 known compounds were isolated from the branches and leaves of Taxodium ascendens. Their structures were mainly determined on the basis of MS, IR, 1D and 2D NMR spectral evidences. Methanol extract showed inhibitory activity on carbonic anhydrase II with an IC₅₀ value of 4.27 µg/ml, acetone extract and methanol extract inhibited activity of cathepsin B with IC₅₀ values of 2.12 and 3.71 µg/ml, respectively.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

<Emphasis Type="Italic">Bursaphelenchus mucronatus</Emphasis> (Nematoda: Aphelenchoididae) vectored by <Emphasis Type="Italic">Monochamus </Emphasis><Emphasis Type="Italic">urussovi</Emphasis> (Coleoptera: Cerambycidae) in Hokkaido,Japan

Bursaphelenchus mucronatus Mamiya et Enda has been recovered for the first time from adults of the cerambycid beetle, Monochamus urussovi (Fischer), in Hokkaido, Japan. The nematode was also recovered from the inner bark of Picea jezoensis (Siebold et Zuccarini) Carrière and Abies sachalinensis (Fr Schmidt) Masters infested with M. urussovi larvae. PCR–RFLP analysis indicated that B. mucronatus in Hokkaido is the European type.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline.     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.