Genetic diversity and heritability estimate of Jatropha curcas L. accessions using agro-morphological and molecular markers

Genetic diversity analysis is the measure of genetic relationship among individual germplasm existing in a population. This research work aims at studying the genetic diversity, heritability pattern and genetic advances in Jatropha curcas germplasm and finally to identify promising groups of accessions that will be used as parent in the future breeding and improvement program. Forty-eight accessions of Jatropha curcas collected from the state of Kelantan, Selangor and Terengganu were planted using randomized complete block design (RCBD). Eleven agro-morphological traits including seed yield/ha were evaluated. Heritability values, principal component analysis were calculated. Cluster analysis was carried out to determine the diversity of Jatropha curcas. Ten ISSR primers were also used to determine molecular diversity in the three populations. In this study, all the morphological traits showed wide variability with highly significant differences among the 48 accessions except for seed width. Positive and significant correlation coefficients were observed among collar diameter, number of secondary branches and number of primary branches. Positive relationship was also observed among seed yield/ha, oil yield/ha and total number of seeds. High broad sense heritability was observed for all traits except for seed width and number of primary branch. The highest heritability was recorded for collar diameter (89.40%), while the least value for this parameter was seed width (-0.02%). Cluster analysis using agromorphological markers and ISSR markers partitions the 48 accessions into 11 and distinct groups at coefficient of 1.1 and 0.6 respectively. From this molecular study, the 48 accessions were clustered into 11 groups at a coefficient of 0.65 without any regard for their geographical origin. The clusters were also formed at medium range coefficient. The mean values of number of alleles, number of effective alleles,shannon’s information index, expected heterozygocity and percentage polymorphic loci are 1.93, 1.69, 0.56, 0.38 and 96% respectively. The percentage variation within and among the populations as shown by analysis of molecular variance are 94% and 6% respectively The principal component analysis revealed that about 75% of total variation as a result of the first three components with PC1, PC2 and PC3 having 61.69, 8.68 and 5.07%, respectively. The three dimensional principal component analysis does not show any distinct relationship among these accessions at a very low coefficient. From the analysis of genetic diversity pattern and estimation of heritability,it can be concluded that collar diameter, number of primary branches, seed yield/accession are useful traits upon which selection can be made. Therefore, accession from cluster II (Accessions B-01-04 and T-01-09) and cluster X (Accessions D-02-02) recommended as parent groups for future breeding programmes

Genetic variation and heritability estimation in Jatropha curcas L. population for seed yield and vegetative traits

An evaluation of six Jatropha curcas L. accessions was carried out at the Field 10, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor. The aim of this study was to determine the seed yield and vegetative traits of the accessions, to estimate the genetic variability and heritability of the population and to study the relationships that exist among these traits. The experiment was conducted using Randomized Complete Block Design (RCBD) with three blocks, six accessions per block and 16 plants per plot. Most of the vegetative and yield traits showed no significant variation among the accessions except in plant height, seed thickness, seed breadth, and total seed per accession. The heritability study showed that the broad sense heritability values ranged from 0 to 23.04%, the highest value was at plant height. This study indicated that environmental factors played an important role than the genetic factor. The correlation study showed that seed length had positive correlation with seed thickness, seed breadth and seed weight. From this study, Accession V5 and V2 showed high potential for future breeding program

Genetic divergence and evaluation of yield potential of Jatropha curcas accessions collected from Peninsular Malaysia

Widening of the narrow genetic base of Jatropha curcas through germplasm collection, diversity study and evaluation is needed to bring about much needed improvement in its seed yield and oil content. This study was carried out to profile the divergence patterns of 45 Jatropha curcas from three populations (Kelantan, Selangor and Terengganu) and to evaluate their yield over a period of three years. Eleven (11) morphological traits together with ISSR markers were used in this study. The percentage of polymorphism for the ISSR markers among the three populations was very high, ranging from 90.38-100%. Shannon information index (I) and expected heterozygosity (He) were found to be highest in the Kelantan population, at 0.58 and 0.40 respectively. Genetic differentiation (Analysis of molecular variance) expressed as fixation index (0.46) revealed that variations within the population accounted for about 100% of the total variation. Interestingly, the cluster analysis based on molecular and morphological traits, as presented in the dendrogram, grouped the 45 accessions into seven and five clusters respectively. For morphological traits, variability in terms of coefficient of variation (CV) was very high, as much as 53.19 and 51 % in total number of seeds and oil yield/ha. Small differences were seen between phenotypic and genotypic coefficient of variation (≤ 10%) for the yield trait. Broad sense heritability for virtually all the yield and yield components was very high (≥ 67.8). Accessions B-01- 03, D-01-06, T-01-06, B-06-02 have been identified and recommended for further evaluation under field conditions before they are chosen for future breeding programmes for seed yield and oil improvement

Genetic diversity analysis among collected purslane (Portulaca oleracea L.) accessions using ISSR markers

Genetic diversity and relationships among 45 collected purslane accessions were evaluated using ISSR markers. The 28 primers gave a total of 167 bands, among which 163 were polymorphic (97.6%). The genetic diversity as estimated by Shannon’s information index was 0.513, revealing a quite high level of genetic diversity in the germplasm. The average number of observed allele, effective allele, expected heterozygosity, polymorphic information content (PIC) and Nei’s index were 5.96, 1.59, 0.43, 0.35 and 0.35, respectively. The UPGMA dendrogram based on Nei’s genetic distance grouped the whole germplasm into 7 distinct clusters. The analysis of molecular variance (AMOVA) revealed that 89% of total variation occurred within population, while 11% were found among populations. Based on the constructed dendrogram using ISSR markers those accessions that are far from each other by virtue of genetic origin and diversity index (like Ac1 and Ac42; Ac19 and Ac45; Ac9 and Ac23; Ac18 and A25; Ac24 and Ac18) are strongly recommended to select as parent for future breeding program to develop high yielding and stress tolerant purslane variety in contribution to global food security

Application of EST-SSR marker in detection of genetic variation among purslane (Portulaca oleracea L.) accessions

Express sequence tag (EST)-simple sequence repeat (SSR) was employed to assess the genetic diversity in elite germplasm collections of purslane (Portulaca oleracea L.) which is a saline and drought tolerant annual herb containing high amount of vitamins, minerals, and antioxidant properties. The 10 primers gave a total of ninety-five bands among which 95 were polymorphic (100 %). The genetic diversity as estimated by Shannon’s information index was 1.85, revealing a high level of genetic diversity in the germplasm. The average numbers of observed allele, effective allele, expected heterozygosity, polymorphic information content (PIC), and Nei’s information index were 9.5, 5.14, 0.81, 0.33, 0.77, and 0.79, respectively. The UPGMA dendrogram based on Nei’s genetic distance grouped the whole germplasm into eight distinct clusters. The analysis of molecular variance (AMOVA) revealed that 71.87 % of total variation occurred within population while 28.13 % from among populations. Considering all these criteria and results from marker-assisted diversity analysis, accessions that are far apart based on their genetic coefficient (like Ac11 and Ac17; Ac4 and Ac42; Ac16 and Ac31; Ac38 and Ac17; Ac21 and Ac31; Ac30 and Ac10) could be selected as parents for further breeding programs

Breeding of high yielding and dwarf oil palm planting materials using Deli dura × Nigerian pisifera population

In practice, progeny and individual palm selection are believed to be the most suitable breeding approach for improvement of quantitative traits in oil palm because their phenotypic expressions are strongly influenced by abiotic factors. Therefore progeny selection approach was applied in this study for the selection of high fresh fruit bunch (FFB) and dwarf oil palm planting materials. Cross between Deli dura and Nigerian pisifera resulted into 34 D × P full sib progenies with 1036 seedlings. For six consecutive years, data were collected on yield and yield component traits, while vegetative traits were recorded once. Bi-parental analysis was carried out using analysis of variance, followed by progenies mean comparison, variance components, heritabilities and cluster analysis. Highly significant (P ≤ 0.01) progeny effect was recorded in this study and this had a pronounced effect on the expression of all the quantitative traits. Progenies performance of FFB varied significantly and it ranged from 166.49 to 220.06 kg/palm/year (kg/p/yr) with trial mean of 192.93 kg/p/yr. Palm height after 8 years of field planting ranged from 1.67 to 2.78 m (control cross) with trial mean of 2.12 m. Broad sense heritability (h2B) was found to be very low (<17.60%) for all the yield traits, however this parameter was high for vegetative traits with palm height having h2B of 90%. Cluster analysis based on all the quantitative traits grouped all the 34 DP progenies into nine distinct clusters. From this study, five progenies (DP3, DP4, DP5, DP8 and DP24) were identified to be high yielding and dwarf palms compare to trial mean. At density of 140 palm/ha, they will produce FFB of 28.63–30.81 t/ha and average of 29.69 t/ha which is about 27.15% higher in FFB when compared to the current planting material with FFB of 23.35 t/ha. In addition, the selected progenies possessed average annual palm increment of 29.82 cm/yr with range of 26 and 32.5 cm/yr which was 57.33% shorter than the current planting material with palm height increment of 45–75 cm/yr

Genetic variability analysis and selection of pisifera palms for commercial production of high yielding and dwarf oil palm planting materials

This study was carried out to evaluate the performance of pisifera (male parent) palms, their general combining ability, and to identify suitable pisifera palms for large scale production of oil palm planting materials. Twenty-four (24) Deli dura palms were nested into 10 Nigerian pisifera male parent palms to produce 1056 tenera (D × P) palms. Tenera palms were planted in two replicates with 16 palms/progeny/replicate. Data collection on yield and yield component traits carried out consecutively for six years. Analysis of variance (ANOVA) followed by the mean comparison and general combining ability were carried out. These were done to know the performance of each of the pisifera parent palms. Additionally, multivariate analysis in form of cluster analysis was done using the quantitative traits. ANOVA showed significant variability among the pisifera palms based on the traits. Fresh fruit bunch (FFB) of each pisifera palm ranged from 173.80 to 211.46 kg/palm/year (kg/p/yr) with a trial mean of 191.92 kg/p/yr, while the oil yield (OY) ranged from 60.24 to 44.06 kg/p/yr with a trial mean of 53.72 kg/p/yr. Based on their mean comparison and the general combining ability, four palms (P01, P03, P09 and P06) have been ranked to be high yielding and good general combiner for FFB and oil yield. While palm P04, P06 and P09 were found to be good combiners for palm height. From these result, four pisifera palms (P01, P03, P09 and P06) have been identified to be high yielding (in terms of FFB and OY), dwarf height and suitable as pollen sources for commercial production of D × P planting materials

Genetic variability in yield and vegetative traits in elite germplasm of MPOB-Nigerian dura × AVROS pisifera progenies

Genetic variability study on vegetative and yield traits was carried out through long-term evaluation of eleven MPOB-Nigerian dura × AVROS pisifera (D× P) progenies at MPOB (Malaysian Palm Oil Board) research station located in Kluang, Johor, Malaysia. The D × P progenies were laid out in randomized complete block design in two blocks with 352 oil palm plants occupying a total area of 2.59 hectares. Data on both vegetative and yield traits such as plant height (HT), leaflet number (LN), leaflet length (LL), leaflet width (LW), rachis length (RL), petiole cross-section, leaf area (LA), leaf area index (LAI), fresh fruit bunch (FFB), average bunch weight (ABW), oil yield (OY), kernel yield (KY), mesocarp to fruit (MTF), kernel to fruit (KTF), oil to bunch (OTB), kernel to bunch (KTB) were collected over the years following the standard method. Analysis of variance of the data showed a significant variation among the progenies performance for both vegetative and yield traits, revealing their differences in their genetic origin. Also significant differences were observed for G×R interactions in all the traits collected except for PCR, KPY and ABW. The progenies plant height ranges from 1.53 (PUP1328) to 2.26 m (PUP1328). Also among the traits is PCS with highest value found in progeny PUP 1174 (32.16 cm2), while the lowest reading was found in PUP 1358 (20.54 cm2). The fresh fruit bunch weight for the progenies ranged from 121.03 to 175.16 kg/ palm/yr. Progeny PUP 1303 was found to have the highest value for FFB (175.16 kg/palm/yr), KPY (7.9 kg/palm/yr) and OPY (38.87 kg/palm/yr). From the correlation study, it was found that FFB, which is the most important yield trait, was positive and highly significant with all other yield and vegetative traits except for MTF, KTF, OTB and KTB where the association was non-significant. In this study, great variability has been found to be present among these progenies and this will be of immense benefit for improvement program. Progeny PUP 1303 and PUP 1246 have been identified as the potential parent and they have been selected for further evaluation trial

Genetic dissection of new genotypes of drumstick tree (Moringa oleifera Lam.) using random amplified polymorphic DNA marker

The knowledge of genetic diversity of tree crop is very important for breeding and improvement program for the purpose of improving the yield and quality of its produce. Genetic diversity study and analysis of genetic relationship among 20 Moringa oleifera were carried out with the aid of twelve primers from, random amplified polymorphic DNA marker. The seeds of twenty M. oleifera genotypes from various origins were collected and germinated and raised in nursery before transplanting to the field at University Agricultural Park (TPU). Genetic diversity parameter, such as Shannon's information index and expected heterozygosity, revealed the presence of high genetic divergence with value of 1.80 and 0.13 for Malaysian population and 0.30 and 0.19 for the international population, respectively. Mean of Nei's gene diversity index for the two populations was estimated to be 0.20. In addition, a dendrogram constructed, using UPGMA cluster analysis based on Nei's genetic distance, grouped the twenty M. oleifera into five distinct clusters. The study revealed a great extent of variation which is essential for successful breeding and improvement program. From this study, M. oleifera genotypes of wide genetic origin, such as T-01, T-06, M-01, and M-02, are recommended to be used as parent in future breeding program

Submergence tolerance in rice: review of mechanism, breeding and, future prospects

Flooding or submergence is one of the major environmental stressors affecting many man-made and natural ecosystems worldwide. The increase in the frequency and duration of heavy rainfall due to climate change has negatively affected plant growth and development, which eventually causes the death of plants if it persists for days. Most crops, especially rice, being a semi-aquatic plant, are greatly affected by flooding, leading to yield losses each year. Genetic variability in the plant response to flooding includes the quiescence scheme, which allows underwater endurance of a prolonged period, escape strategy through stem elongation, and alterations in plant architecture and metabolism. Investigating the mechanism for flooding survival in wild species and modern rice has yielded significant insight into developmental, physiological, and molecular strategies for submergence and waterlogging survival. Significant progress in the breeding of submergence tolerant rice varieties has been made during the last decade following the successful identification and mapping of a quantitative trait locus for submergence tolerance, designated as SUBMERGENCE 1 (SUB1) from the FR13A landrace. Using marker-assisted backcrossing, the SUB1 QTL (quantitative trait locus) has been incorporated into many elite varieties within a short time and with high precision as compared with conventional breeding methods. Despite the advancement in submergence tolerance, for future studies, there is a need for practical approaches exploring genome-wide association studies (GWA) and QTL in combination with specific tolerance traits, such as drought, salinity, disease and insect resistance