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The objective of this study was to determine Cd accumulation under water-deficit conditions by young cacao plants. The study was conducted under greenhouse conditions. Two full-sib families (IMC67 × PA121 and SCA6 × PA121), obtained through controlled crosses, and an open pollinated half-sib seedling family of IMC67, widely used as rootstock in Colombia, were employed. Plants were grown in Cd-contaminated soil (0.356 mg kg−1) without external sources of the metal. They were subjected to water deficit by suspending irrigation for consecutive periods of 19 and 27 days (D19 and D27), followed by rehydration. Water stress reduced leaf water potential (Ψleaf) with values from −1.51 to −2.09 MPa, with full-sib family SCA6 × PA121 being the most tolerant to water deficit. Cd concentration was influenced by biomass reduction (observed in IMC67 × PA121 and SCA6 × PA121) and transpiration rate (evident in IMC67) caused by water deficit. Full-sib progenies IMC67 × PA121 and SCA6 × PA121 accumulated more Cd in the plants than open pollinated IMC67, with higher Cd accumulation in leaves. The translocation factor (TF) revealed that the aboveground organs of the progenies were enriched with Cd (TF > 4). Water deficit increased Cd translocation from roots to leaves in IMC67 × PA121 and IMC 67, while there were no significant changes in SCA6 × PA121. Full-sib family SCA6 × PA121 stood out as the most promising progenies due to their water-stress tolerance and Cd accumulation stability. This study introduces a discussion about the influence of water stress on Cd accumulation in Theobroma cacao. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine Cd accumulation under water-deficit conditions by young cacao plants. The study was conducted under greenhouse conditions. Two full-sib families (IMC67 × PA121 and SCA6 × PA121), obtained through controlled crosses, and an open pollinated half-sib seedling family of IMC67, widely used as rootstock in Colombia, were employed. Plants were grown in Cd-contaminated soil (0.356 mg kg−1) without external sources of the metal. They were subjected to water deficit by suspending irrigation for consecutive periods of 19 and 27 days (D19 and D27), followed by rehydration. Water stress reduced leaf water potential (Ψleaf) with values from −1.51 to −2.09 MPa, with full-sib family SCA6 × PA121 being the most tolerant to water deficit. Cd concentration was influenced by biomass reduction (observed in IMC67 × PA121 and SCA6 × PA121) and transpiration rate (evident in IMC67) caused by water deficit. Full-sib progenies IMC67 × PA121 and SCA6 × PA121 accumulated more Cd in the plants than open pollinated IMC67, with higher Cd accumulation in leaves. The translocation factor (TF) revealed that the aboveground organs of the progenies were enriched with Cd (TF > 4). Water deficit increased Cd translocation from roots to leaves in IMC67 × PA121 and IMC 67, while there were no significant changes in SCA6 × PA121. Full-sib family SCA6 × PA121 stood out as the most promising progenies due to their water-stress tolerance and Cd accumulation stability. This study introduces a discussion about the influence of water stress on Cd accumulation in Theobroma cacao.

This study investigated oil palm inflorescence sex ratio (ISR) and fruit set (FS) yield among 24 dura × pisifera biparental progenies on fibric peat soil, hybridized from ten genetic origins. Three-month intervals of data collection on ISR and “S-shape” procedure for FS determination were carried out in an independent complete randomized design for one year. Based on the assessment of individual progenies, analysis of variance revealed the existence of genetic heterogeneity. Five of the progenies had the highest ISR above 90%. However, 20.83% of the progenies (PK4841, PK4674, ECPHP415, ECPHP550, and PK4118) had the best normal range of ISR, indicating FS declined being influenced by ISR. Therefore, only 12.50% of the progenies (PK4674, PK4465, and PK4482) were above 60% FS critical level. Correlation analysis verified that ISR depends on the female flower and progeny PK4674 (65.78%) and PK4465 (62.62%) had the best FS and fruit to bunch. Among the parental origins, Deli Serdang × Cameroon was statistically the best for male flower production at 29.40% and ISR at 72.22%. The highest FS was recorded in Deli Banting × AVROS (54.00%) and Angola × AVROS (53.78%). However, molecular research, such as microsatellite molecular markers if concurrently used as a selection criterion with the present conventional study, could present further details to complement the present findings.

This study investigated oil palm inflorescence sex ratio (ISR) and fruit set (FS) yield among 24 dura × pisifera biparental progenies on fibric peat soil, hybridized from ten genetic origins. Three-month intervals of data collection on ISR and "S-shape" procedure for FS determination were carried out in an independent complete randomized design for one year. Based on the assessment of individual progenies, analysis of variance revealed the existence of genetic heterogeneity. Five of the progenies had the highest ISR above 90%. However, 20.83% of the progenies (PK4841, PK4674, ECPHP415, ECPHP550, and PK4118) had the best normal range of ISR, indicating FS declined being influenced by ISR. Therefore, only 12.50% of the progenies (PK4674, PK4465, and PK4482) were above 60% FS critical level. Correlation analysis verified that ISR depends on the female flower and progeny PK4674 (65.78%) and PK4465 (62.62%) had the best FS and fruit to bunch. Among the parental origins, Deli Serdang × Cameroon was statistically the best for male flower production at 29.40% and ISR at 72.22%. The highest FS was recorded in Deli Banting × AVROS (54.00%) and Angola × AVROS (53.78%). However, molecular research, such as microsatellite molecular markers if concurrently used as a selection criterion with the present conventional study, could present further details to complement the present findings. [ABSTRACT FROM AUTHOR]

This research was conducted to study the performance of biparental dura × pisifera (D × P) progenies and their parental genetic origins on fruit set and yield components. Twenty-four D × P progenies developed from 10 genetic origins were used for this study. Analysis of variance showed that there was genetic variability based on the evaluation of individual progenies. Deli Ulu Remis × Nigeria of progeny ECPHP500 recorded the highest bunch number (22.91), and fresh fruit bunch (184.62 kg palm−1 year−1) and Deli Banting dura × AVROS pisifera (ECPHP550) had the highest average bunch weight (10.36 kg bunch−1 year−1). Progenies PK4674 (61.12%) and PK4465 (60.93%) had the highest fruit set, and the highest oil yield of 52.66 kg bunch−1 was noticed by progeny PK4674. Estimation of variance components, coefficients of variation, heritability, and genetic gain were calculated to establish the genetic variability. To validate the genetic disparity among the progenies, an unweighted pair-group procedure with arithmetic mean (UPGMA) and principal component was employed based on their quantitative traits. Through the UPGMA and principal component, the 24 progenies were clustered into 7 clusters, whereas cluster V had the highest fruit set (60.62%) and cluster IV had the highest oil yield (43.71 kg palm−1 year−1). For oil palm tissue culture and breeding programs, progeny PK4674 will be more useful for developing planting materials of high oil yielding with stable performance. However, we recommend that future studies incorporate molecular studies with conventional breeding. [ABSTRACT FROM AUTHOR]