scholarly journals PENDUGAAN DAYA GABUNG DAN HETEROSIS KETAHANAN TANAMAN KAKAO (Theobroma cacao L.) TERHADAP PENYAKIT BUSUK BUAH (Phytophthora palmivora)

2020 ◽  
Vol 17 (3) ◽  
pp. 124
Author(s):  
RUBIYO RUBIYO ◽  
TRIKOESOEMANINGTYAS TRIKOESOEMANINGTYAS ◽  
SUDARSONO SUDARSONO
Keyword(s):  
Combining Ability ◽  
Theobroma Cacao ◽  
Genetic Parameters ◽  
General Combining Ability ◽  
Phytophthora Palmivora ◽  
F1 Hybrid ◽  
Plastic Bag ◽  
Black Pod ◽  
Black Pod Disease ◽  
Theobroma Cacao L

<p>ABSTRAK</p><p>Klon kakao unggul berdaya hasil dan bermutu hasil tinggi sertaresisten terhadap penyakit utama perlu dikembangkan melalui pemuliaantanaman dan tersedianya informasi tentang parameter genetik diharapkandapat membantu memecahkan masalah tersebut. Pendugaan parametergenetik dapat dilakukan dengan analisis persilang dialel. Penelitianbertujuan untuk menduga parameter genetik ketahanan tanaman kakaoterhadap infeksi P. palmivora, menggunakan analisis persilangan setengahdialel. Bahan tanaman terdiri atas lima klon kakao (ICCRI 3, TSH 858,DR 1, ICS 13 dan Sca 6) yang tergolong rentan hingga tahan terhadapinfeksi P. palmivora yang digunakan sebagai tetua dan 10 galur hibrida F1hasil persilangan antar lima klon. Penelitian dilaksanakan di KebunPercobaan Kaliwining Pusat Penelitian Kopi dan Kakao Indonesia,Jember, Jawa Timur dari tahun 2008 hingga 2009. Untuk setiap kombinasipersilangan dievaluasi 20 bibit dan diulang tiga kali. Untuk mengetahuirespon bibit hibrida F1 terhadap infeksi P. palmivora, daunnya diinokulasidengan inokulum zoospora dan disungkup dengan plastik untuk menjagakelembapannya (&gt;90%). Pengamatan luas bercak akibat infeksi P.palmivora dilakukan enam hari setelah inokulasi dan digunakan untukmenghitung intensitas penyakit. Hasil penelitian menunjukkan bahwakakao klon DR 1, ICS 13, dan ICCRI 3 mempunyai DGU yang palingtinggi dibandingkan dengan tetua lainnya. Selanjutnya, persilangan antarklon kakao DR 1 x ICS 13, dan TSH 858 x Sca 6 mempunyai DGKtertinggi sehingga kombinasi persilangan ini berpeluang untuk menjadipenghasil hibrida baru yang resisten terhadap P. palmivora. Kombinasipersilangan yang menunjukkan nilai heterosis tertinggi adalah DR1 x ICS13, DR1 x Sca 6, dan ICS 13 x Sca 6.</p><p>Kata kunci: Heterosis, hibrida F1, DGU, DGK, intensitas penyakit</p><p>ABSTRACT</p><p>Estimation of Heterosis and Combining Ability forResistance Against Black Pod Disease (Phytophthorapalmivora) in Cacao (Theobroma cacao L.)</p><p>High yielding and disease resistance of cacao clone needs to bedeveloped through breeding program. Availability of genetic parametersfor various agronomic importance characters in cacao would be veryuseful and beneficial for cacao breeding activities. Estimation of variousgenetic parameters could be done by analyzing F1 arrays generated fromsemi-diallele crosses among a number of parents. The objectives of thisresearch were to estimate genetic parameters for resistance against P.palmivora infection in cacao using F1 arrays generated from semi-diallelecrosses among five cacao clones. Five cacao clones (DR 1, TSH 858, ICS13, ICCRI 3, and Sca 6), representing an arrays of clones with increasedresistance against P. palmivora infection, were used as parents to generate10 F1 hybrid arrays. This research was conducted at KaliwiningExperimental Station, Indonesian Coffee and Cacao Research Institute,Jember, Indonesia, during the period of 2008 to 2009. At most 20seedlings were evaluated for each F1 hybrid and the evaluation wasreplicated three times. To evaluate the response of the seedlings against P.palmivora infection, their leaves were inoculated with zoospore of P.palmivora. Relative humidity around inoculated leaves was maintained at&gt;90% by wrapping them with plastic bag. The sizes of leaf necroseresponse due to P. palmivora infection were observed during six days afterinoculation and the disease intensity was calculated based on this recordedsymptoms. Results of the experiments indicated that cacao clones (DR 1,ICS 13, and ICCRI 3) were the highest in general combining ability(GCA) for resistance character than the other two clones. Moreover, F1hybrid originated from crosses between DR 1 x ICS 13, and TSH 858 xSca 6 were the highest in specific combining ability (SCA) for resistancecharacter. Therefore, this combination crosses might be used to developenew hybrid combinations resistance against P. palmivora infection.Combination crosses showing highest heterotic value for resistance againstP. palmivora infection were DR 1 x ICS 13, DR1 x Sca 6, and ICS 13 xSca 6.</p><p>Key words : Heterotic effects, F1 hybrid array, GCA, SCA, diseaseintensity</p>

Genetic diversity of native cultivated cacao accessions (Theobroma cacao L.) in Nicaragua

2012 ◽  
Vol 10 (3) ◽  
pp. 254-257
Author(s):  
Erwin Aragon ◽  
Claudia Rivera ◽  
Helena Korpelainen ◽  
Aldo Rojas ◽  
Paula Elomaa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Theobroma Cacao ◽  
Phytophthora Palmivora ◽  
Genetic Composition ◽  
Breeding Programmes ◽  
Black Pod ◽  
Black Pod Disease ◽  
Parental Lines ◽  
Resistant Genotypes ◽  
Theobroma Cacao L

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.

scholarly journals The expression of pathogenicity-related genes in Phytophthora palmivora causing black pod rot disease on cacao (Theobroma cacao L.) in Indonesia

2021 ◽  
Vol 16 (1) ◽  
pp. 284-295
Author(s):  
Masanto Masanto ◽  
Arif Wibowo ◽  
Nur Fathurahman Ridwan ◽  
Widhi Dyah Sawitri ◽  
Koji Kageyama ◽  
...  
Keyword(s):  
Theobroma Cacao ◽  
Phytophthora Palmivora ◽  
Black Pod ◽  
Rot Disease ◽  
Theobroma Cacao L

scholarly journals Symbiotic and endophytic fungi as biocontrols against cocoa (Theobroma cacao L.) phytopathogens

2017 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Raquel Amanda Villamizar-Gallardo ◽  
Oscar Orlando Ortíz-Rodriguez ◽  
Jhon Wilmer Escobar
Keyword(s):  
Theobroma Cacao ◽  
Trichoderma Viride ◽  
Phytophthora Palmivora ◽  
Mycotoxigenic Fungi ◽  
Black Pod ◽  
Antagonistic Potential ◽  
Native Strains ◽  
Biological Methods ◽  
Theobroma Cacao L

ABSTRACT Cocoa (Theobroma cacao L.) is a tropical tree, seriously affected by fungal diseases. To control several pathogens, biological methods are prescribed since they are friendly to the environment and easy to use. The main objective of this study was to assess the biocontrol effect of two native strains, Trichoderma viride and Botryosphaeria quercum, on phytopathogens such as Phytophthora palmivora and Moniliophtora roreri, causal agents of black pod and frosty pod rot diseases, respectively. In addition, biocontrolers were faced on potential mycotoxigenic fungi such as Aspergills flavus and Fusarium solani, which are very common on cocoa. The Bio-Control Index (BCI) was calculated to determine the in vitro biocontrol effect against the four phytopathogens. Results indicated that the best biocontrol agent of phytopathogens was B. quercum, showing BCI of 82.3%, 80.7%, 63.3% and 59.7% for each tested phytopathogen, respectively. Competition for substrate was the dominant biocontrol strategy. As to the origin of strains, those coming from the Department Norte de Santander and Santander showed the highest average inhibition percentage. This study provides an initial screening to the endophytic and antagonistic potential of fungi, specifically those capable of colonizing cocoa pods and soils. Thus, these strains can be used as an efficient biological control alternative against several known phytopathogens of cocoa in the field.

scholarly journals Effect of MgSO4 nutrition on Theobroma cacao L. susceptibility to Phytophthora megakarya infection

2018 ◽  
Vol 54 (No. 2) ◽  
pp. 74-82
Author(s):  
Minyaka Emile ◽  
Banen Collette Vanessa Madina ◽  
Kusznierewicz Barbara ◽  
Doungous Oumar ◽  
Haouni Soungouna ◽  
...  
Keyword(s):  
Theobroma Cacao ◽  
Substantial Decrease ◽  
Asymptotic Line ◽  
New Strategy ◽  
Hyperbolic Curve ◽  
Cysteine Content ◽  
Black Pod ◽  
Phytophthora Megakarya ◽  
Black Pod Disease ◽  
Theobroma Cacao L

A new strategy to reduce the severity of black pod disease (BPD) in T. cacao plants using MgSO<sub>4</sub> nutrition was investigated. The dynamics of the tolerance to BPD of 18 susceptible T. cacao plantlets coming from the cross (♀SNK64 × ♂UPA14) was monitored during weekly (8 weeks) supply of MgSO<sub>4</sub> into the soil. Prior to MgSO<sub>4</sub> application, disease scores of the 18 plantlets (in six sets of three plantlets per set) were varying between 3.5 (susceptible) and 5 (highly susceptible). After MgSO<sub>4 </sub>application, a substantial decrease in disease scores was observed compared to the control. The percentage of disease tolerance gain of plantlets versus MgSO<sub>4</sub> supplied (0–2.96 g) presented a quasi-hyperbolic curve with asymptotic line corresponding to 60% (day 28) and 70% (day 56). Cysteine content was not significantly different between the six triplets before MgSO<sub>4 </sub>nutrition. On days 28 and 56 of MgSO<sub>4</sub> supplementation, cysteine content presented a pattern similar to the tolerance gain of plantlet sets. The monitoring of glutathione content versus MgSO<sub>4</sub> supplementation (compared to day 0) showed sigmoid (day 28) and hyperbolic (day 56) curves which were associated with defined mathematical laws determined by MALAB software. Negative and highly significant correlations were observed between disease scores, cysteine and glutathione contents in leaves while positive and highly significant correlations were observed between cysteine and glutathione contents in leaves. These data might mean that MgSO<sub>4</sub> nutrition significantly improved the tolerance of T. cacao. The mechanism of tolerance improvement might be associated with the synthesis of sulphur-containing compounds (cysteine and glutathione) which might be directly or indirectly used by T. cacao against P. megakarya.

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