Rootstock Characteristics of Three Combinations of Theobroma cacao L. Crosses on Different Water Availability

Abstract

Climate change is universal phenomena which is importantly anticipated including cocoa plantation. Drought tolerance cocoa seedling is urgently neededto develop cocoa plantation. This paper studied possible drought tolerance of cocoa seedling through crossing between female parent KKM 22 with three maleparents BAL 209, KW 641, and KW 614. Progeny test was conducted in green house based on four water availability conditions: 25, 50, 75, and 100%. Root condition was recorded as rootstock parameters of three crossings. Result showed that root characteristics varied among crossing samples studied. The longestand hight volume root were recorded from KKM 22 x BAL 209 crossing. Seedling of KKM 22 x BAL 209 crossing tended to have long and wide root, while seedling of KKM 22 x KW 641 crossing tended to have a wide root type and seedling of KKM 22 x KW 614 tended to have a long root type. Based on drought tolerancy, seedling of KKM 22 x KW 641 crossing could be classified as drought tolerance while other two group progenies could be classified as susceptible to drought.To conclude, seedling of KKM 22 x KW 641 can be recommended for cocoa plantation in drought area.

Genetic components estimation of F1 population of cocoa (Theobromacacao L.) in drought stress condition.

“…Research about drought stress in plants has been carried out. Some studies suggest that the characters associated with the root system have important role in response to drought stress in plant (Alban et al, 2016;Medina & Laliberte, 2017;Setyawan et al, 2018). These characters include stem diameter, root length, root volume, shoot and root fresh weight, shoot and root dry weight, and root/ shoot ratio.…”

“…The mean value shown can only rank which genotypes are best for a particular character. Some studies on tolerance to stress indicate that determining a tolerant genotype requires a calculation such as stress susceptibility index (SSI) (Helmi, 2017;Setyawan et al, 2018).…”

“…The sensitivity index of drought stress is reflected through the value of SSI. SSI values (Helmi, 2017;Setyawan et al, 2018). Genotypes classified as tolerant to drought stress were Sulawesi 3, TSH 858, and KW 516 x ICCRI 09 (Figure 1).…”

“…Clones grouping used their tolerance ability to drought based on the value of the Stress Susceptibility Index (SSI) (Ali & El-Sadek, 2016;Khan & Dhurve, 2016) with the formula: Cocoa plants with SSI value of <0.5 are classified as drought tolerant plants, plants with 0.5 <SSI <1 are classified as moderate to drought stress (Setyawan et al, 2018), and plants with SSI>1 are classified as susceptible to drought stress (Helmi, 2017).…”

Seedling Performance of Cocoa Genotypes (Theobroma cacao L.) in Drought Stress Condition.

“…Several studies in drought stress have been carried out, especially on cocoa crops. Drought stress research in cocoa plants is carried out in the seedling phase referred to Alban et al (2015), Santos et al (2016), Alban et al (2016), Ayegboyin & Akinrinde (2016), Setyawan et al (2018), and Zakariyya & Indradewa (2018). Seedling phase is a critical PELITA PERKEBUNAN, Volume 35, Number 3, December 2019 Edition phase of plants in drought stress conditions (Azzeme et al, 2016).…”