No abstract

The oil palm Elaeis guineensis is the highest oil‐yielding crop and has the potential to become the major supplier of both edible oil and renewable industrial feedstock. The oil yield from wild groves is presently less than 0.5 t/ha/y. However, through breeding and selection, the oil yield of commercial plantations could reach as much as 8 t/ha/y. New planting materials also have the capability of better oil yields with high iodine value (IV), slow height increment, and larger kernels. The oil also contains considerable amounts of carotenoids (500–700 ppm), vitamin E (600–1000 ppm), and sterols (250–620 ppm). The oil yield of another oil palm species, E. oleifera, is approximately 0.5 t/ha/y with high contents of carotenoids (700–1500 ppm), vitamin E (700–1500 ppm), and sterols (3500–4000 ppm). The above traits could be improved through breeding and biotechnology. Biotechnological efforts at the Palm Oil Institute of Malaysia are directed toward the production of oil with high IV and high monounsaturated fatty acids for edible purposes and industrial uses. Isolation and manipulation of the genes involved in the biosynthesis of fatty acids are the main focus. The aim is to increase the efficiency of conversion of palmitate (C16:0) to oleate (C18:1). Levels of palmitate and oleate are controlled by the enzymes acyl‐acyl carrier protein (ACP) thioesterase and β‐keto acyl ACP synthase II. The chain termination reactions of C16:0 and C18:1 are independent, thus paving the way for the possibility of reducing palmitate levels by switching off the palmitoyl ACP thioesterase gene.

ABSTRACT. We evaluated 38 dura x pisifera (DP) oil palm progenies in four locations in Malaysia for genotype by environment interaction and genotypic stability studies. The DP progenies derived from crosses between pisifera palms of AVROS, Serdang S27B, Serdang 29/36, and Lever Cameroon were chosen to be the males' parent and Deli dura palms designated as females' parent. All the locations differed in terms of soil physical and chemical properties, and the soil types ranged from coastal clay to inland soils. The genotype by environment interaction and stability of the individual genotypes were analyzed for oil yield trait using several stability techniques. A genotype by environment interaction was detected for oil yield and it had a larger variance component than genotypic variance (σ interaction of oil yield was largely explained by a non-linear relationship between genotypic and environmental values. Overall assessment of individual genotypic stability showed that seven genotypes were highly stable and had consistent performance over the environments for the oil yield trait [total individual genotype stability scored more than 10 and mean oil yielded above the average of the environment (genotype means are more than 34.37 kg·palm -1 ·year -1 )]. These genotypes will be useful for oil palm breeding and tissue culture programs for developing high oil yielding planting materials with stable performance.

Three populations of oats, each with 790 lines, were derived from CI 7555: (a) one (M population) consisted of Mz-derived lines obtained from EMS treatment of naked seeds, (b) one (0 population) consisted of F 2derived lines from crosses of M 1 with check plants, and (c) one (C population) consisted of check lines.About 98~ of the grain yield (GYD) variation in each population was due to variation in growth rate (GR) and harvest index (HI).There was greater variation for both GR and HI in M and 0 than in the C population, showing that mutations were induced for both traits. Generally, mutations for these two traits were for reduced expression: high HI and GR are desired in a practical oat breeding program, so most induced mutations were deleterious.Mutation breeding, either with direct selection or outcrossing to release the induced mutations, does not appear to be a desirable method for improving GR or HI of oats.

From a large number of rice varieties tested, no variety was identified as resistant to tungro bacilliform virus (RTBV). Only in Utri Merah was the RTBV multiplication restrictive, whereas other varieties such as Kataribhog and Pankhari 203 were identified as tolerant. These varieties were crossed with a susceptible variety. TN1, to study the inheritance of restrictive multiplication and tolerance to RTBV. After 3 weeks of inoculation with RTBV, F1; F2, and F3 progenies were assessed by enzyme-linked immunosorbent assay (ELISA). The RTBV concentration in all F1 populations was intermediate between parents. The frequency distribution of F2 seedlings with various levels of RTBV concentration indicated that the RTBV tolerance is controlled by multiple genes. The RTBV concentrations in F1 and F2 progenies from the Utri Merah x TN1 cross revealed that restrictive multiplication of RTBV in Utri Merah is a polygenic character. The continuous variation observed in F2 populations from crosses between tolerant varieties and Utri merah indicated no allelic relationships between tolerant and restrictive multiplication traits.