Breeding Value of Cocoa (<i>Theobroma cacao</i> L.) for Pod and Bean Traits: A Consequential Advance in Nigerian Cocoa Breeding Program

Abstract

The understanding of the generated hybrids' breeding value gives a measure of probable advances in a breeding program. Four cocoa genotypes (testers) were crossed with two distinct lines (T65/7 and T86/2). The parents and the hybrids were separately established in randomized complete block design with six replications. The fourteen genotypes were evaluated for pod length (PL), weight (PW), beans/pod (NoB), bean length (BL), width (Bwi) and thickness (BT). The treatment, parent, crosses and Line x Tester sources of variation were significant (P ≤ 0.05). Hybrids from the same maternal parent differed significantly (P < 0.05) for the six traits. Contribution to the total variance of PL, PW and Bwi were in the following order: Tester > Line x Tester > Lines. The highest general combining ability (0.42) occurred in T65/7 for PW; the least (-0.081) occurred in T86/2 for PL. Cross combination T65/7xT57/22 produced the highest specific ability of combination (4.33) for NoB. Variance of GCA and SCA were significant (P < 0.05) for the six traits. The GCA/SCA ratios revealed the inheritance of PL, PW, Bwi and BT to be additive. Non-additive gene effect controlled NoB and BL. Heterosis for the six traits ranged between -17.82% for BT (T65/7xT57/22) to 52.40% for PW (T65/7xT53/8). Increased productivity in cocoa is possible through hybrid breeding programs.

Morphological characterization of elite cacao trees (<i>Theobroma cacao</i> L.) in Tumaco, Nariño, Colombia

“…Adewale et al (2014) In the PCA, the first five components explained RI WKH WRWDO YDULDELOLW\ WKH IDFWRUV WKDW contributed the most to the variability were related to the fruit, edge length, thickness of the shell and width/length ratio of the fruit. In the 0&$ WKH ILUVW ILYH YDOXHV DFFRXQWHG IRU of the variability.…”

Pendugaan Daya Gabung dan Heritabilitas Beberapa Karakter Agronomis pada Populasi Generasi F1 Kakao (Theobroma cacao L.)

“…Peningkatan potensi daya hasil kakao dapat dicapai melalui program perakitan varietas hibrida (Adewale, Adeigbe, Sobowale, & Dada, 2014). Keberhasilan program tersebut sangat dipengaruhi oleh ketersedian sumber daya, tujuan, dan perilaku genetik dari sifat-sifat unggul yang diinginkan (Yao et al, 2013).…”

“…Daya gabung bermanfaat dalam mempelajari dan membandingkan penampilan galurgalur di dalam kombinasi hibridanya (Griffing, 1956). Daya gabung umum (DGU) maupun daya gabung khusus (DGK) dapat dijadikan sebagai penduga nilai (value) masing-masing tetua dalam suatu persilangan (Adewale et al, 2014) sehingga pemulia tanaman dapat secara efisien menentukan tetua-tetua terbaik dalam program perakitan varietas hibrida.…”