Development of PCA SYN VAR 001: synthetic variety of coconut

PCA observed that coconut farmers traditionally plant seed nuts taken from their own high-yielding palms, with the belief that equally high yield plants would be obtained in the succeeding cropping. Farmers are not aware that such practice leads to inbreeding, wherein the plants produced are not true-to-type, or they do not have the same traits as the parent plants. To address the problem of availability of planting materials, Rivera et al. (PCA-ZRC), developed SYN VAR, a synthetic variety of coconut. SYN VAR is recognized as the first of its kind in the world. PCA started on SYN VAR in 1979. The researchers modified the classical breeding method to develop a scheme to produce the base population of a synthetic coconut variety. A base population of palms having a high degree of balanced heterozygosity was produced and a breeding scheme was developed that would allow individual palms to mate at random and maintain high heterozygosity from generation to generation. The modified scheme used single crosses of six tall coconut cultivars and varieties, four local and two foreign, which had good combining ability. SYN VAR is an open pollinated variety purposely created to be more adaptable and stable over many generations due to its wide genetic base. The inter-crossed or open-pollinated nuts from SYN1 constituted the second-generation synthetics and from these, no considerable loss in vigor was expected onwards. Twelve years after field planting the hybrid base population, SYN VAR demonstrated its yield stability, with mean yield of 2.5-3.5 t copra/ha. Majority of the first filial hybrid base population performed above the mean yield, and those that performed below the mean yield did not fall below 1.5 t copra/ha, which was still higher than the national average copra yield of 0.8 t copra/ha. Modern molecular marker technology, like the microsatellite or Simple Sequence Repeat (SSR) markers, was used to identify and select superior materials at the seedling stage. The use of SSRs enable breeders to discern similar varieties based on their visible characteristics. It also helped them know the plant types that would not breed true-to-type with respect to a specified character even at the nursery stage. A total of 45 alleles using five SSR primer pairs was found in SYN VAR, with Shannon Information Index of 1.91. The genetic structure of the first filial generation of SYN VAR was not stable, but the high quality fruit components of its parents favored the use of the second generation as planting materials to attain higher copra yield. On the other hand, the first filial generation showed genotypes appropriate for tissue culture and genome mapping experiments. SYN VAR was considered farmers' variety as it offered tremendous opportunities for all coconut farmers. Farmers may use the SYN VAR seeds directly for a second crop and expect improved yields. To date, 374,913 SYN VAR seednuts and seedlings have been distributed nationwide for regional planting activities and for the establishment of coconut seed farms that would supply the requirement for planting 1,678 ha. The current SYN VAR nut production rate at PCA-ZRC was capable of planting 360 ha, and this would rise to 650 ha/year over the next 50 years. In turn, the SYN VAR seednuts planted would be capable of planting 9,700 ha/year in about 7 years. If the trend continues, the genetic materials in the base population would enable selective temporal and spatial harvesting to generate relevant genotypes for other studies. Complementing the present classical coconut breeding strategies, application of the DNA technology would facilitate the development of open-pollinated varieties from 15 variety hybrids developed by PCA, pave the way for efficient assessment of breeder's breeding populations, and generate sufficient information on the genetic diversity level of existing coconut stands in farmers' fields. A continuing replanting program would also be ensured, overcoming the basic problem of inadequate seednuts and minimal government intervention.