Released five interim clones for the estate sector and two interim clones for the smallholder sector.

Interim clones for the Estate sector

• INT 1 (HP 2002/201)
• INT 2 (HP 91/58)
• INT 3 (GPS III)
• INT 4 (GPS IV)
• INT 5 (HP 95/55)

Interim clones for the Smallholder sector

• RRISL 2006
• RRISL Centennial 4

Two non-Wickham germplasm selections were successfully used as the female parent for the first time in the local hybridization history and thirty-six new genotypes were raised successfully.

Utilized strong early selection criteria such as crop physiology, latex physiology, and molecular screening of yield and stress-responsive characters to strengthen and reduce the period of breeding cycle.

Two genotypes selected from small-scale clone trials were established at the Estate collaborative clone trials (ECT) at Eladuwa estate for further characterization under Group III recommendation.

Molecular screening of clones for drought stress identified 6 promising clones for marginal areas.

• RRISL2001
• RRIC121
• RRISL2006
• RRISL2005
• RRISL C4
• RRISL C3

Tapping commences at the clonal evaluation trial at non-traditional rubber growing areas to evaluate the best-performing clone for water stress conditions.

Seventeen clones received from India, Myanmar, Thailand, and Cote d’Ivoiry were established to test their adaptability and performances at large-scale clonal trials.

Revised clone recommendations December 2023

Successful story of genetic improvements of Hevea breeding pool in Sri Lanka

The Genetics and Plant Breeding Department is the pioneer in Hevea breeding and a remarkable contribution has been made to the industry by improving the genetic material of the plants. We have developed plenty of new high-yielding clones, and presently the genetic potential of rubber yield has reached around 3,000 - 3,500 kg ha-1 yr-1

RRISL signed several bi and multi-lateral clone exchanges over the past century. There is evidence, even in the current clone recommendation, that it has 10 foreign clones from India, Malaysia, and Indonesia. In 2015, a Memorandum of Understanding (MoU) was signed by fifteen rubber-growing countries to exchange 49 rubber clones between them to promote international cooperation and capacity building in the IRRDB member countries for the betterment of the natural rubber industry and evaluate the performance of all the exchange clones in the different agro-climatic conditions in the member countries.

Introduced underutilized clones to the bud wood nurseries of RDD and RPCs to improve the clone balance of the country.

Introduced five unregistered clones and two Indian clones as interim clones to the revised clone recommendation to supply new clones to the industry quickly to encourage the planters to grow a wide variety of clones to maintain good genetic diversity in plantations. They are recommended to be planted up to two hectares in a plantation in Estate/RRI collaborative clone trials.

According to the Quantitative gene expression analysis of selected genes to screen drought tolerance of selected Hevea clones, six promising clones were identified for marginal areas. Here, valuate the level of drought-responsible genes Catalase (CAT), ascorbate peroxidase (APX), and Glutathione peroxidase (GPX) expression of selected Hevea clones under drought stress conditions. Further research is continued to confirm the results.

Analysis of antioxidant gene expression in tapping panel dryness was done. The preliminary results of analysis of antioxidant gene expression in tapping panel dryness (TPD) affected rubber trees showed that the HbMnSOD and HbCAT genes were down-regulated in TPD-affected rubber clones and might have led to the accumulation of Reactive Oxygen Species (ROS), which may cause TPD.

DNA markers were used for the early identification of superior genotypes in the breeding populations. A precise selection of high-yielding rubber genotypes was done based on Rubber Elongation Factor (REF) gene expression.

Released five interim clones for the estate sector and two interim clones for the smallholder sector.

Two non-Wickham germplasm selections were successfully used as the female parent first time in the local hybridization history and thirty-six new genotypes were raised successfully.

Two genotypes selected from small-scale clone trials were established at ECT at Eladuwa estate for further characterization under Group III recommendation.

Clones established

• HP 98-132
• HP 2002-201 (INT 01)

Molecular screening of clones for drought stress identified 6 promising clones for marginal areas.

Tapping commences at the clonal evaluation trial at non-traditional rubber growing areas to evaluate the best-performing clone for water stress conditions.

Two trials were established at non-traditional rubber growing areas with drought-resistant clones identified at the molecular level.

Annual Hand Pollination Programme

Evaluation of new genotypes produced from the hand pollination programme at the mother plant nursery level.

Evaluation of new genotypes identified from the progeny of hand pollination programme under small scale level (SSCT).

Evaluation of selected HP entries from the Estate/ RRI collaborative clone trials. (ECTs)

Evaluation of selected HP entries from the SSCTs and ECTs’ at the smallholder level (SRT).

Testing of performance in new promising clones in different ecological zones.

Providing training facilities and demonstrations for undergraduate and postgraduate students, school teachers and students.

Providing facilities for Research undertaking students for their undergraduate and postgraduate degrees.

Clone identification services based on stakeholders’ request.