Growth, flowering and gas exchange of Rellia brittoniana treated with different concentrations and application frequencies of daminozide

Ruellia brittoniana is a fast growth plant with a strong tendency of vegetative growth that occurs at the expense of flowering capability, thus regular pruning for height control is necessary. Chemical pruning using suitable growth retardant may offer similar effects on stem and branch elongation, and flowering of the plants could be promoted. This study was carried out to evaluate the varying rate of daminozide and frequencies of application on the growth and flowering of Ruellia brittoniana.Results of a two factorial experiment involving two application frequencies (double and triple application) and five concentrations of daminozide (0, 500, 1000, 1500, 2000 mg L-1) showed that different concentration of daminozide and application frequencies significantly affected the vegetative growth, photosynthesis, transpiration and chlorophyll content.Daminozide at 500 mg L-1 with triple application caused a reduction of 42% in plant height compared to control with less detrimental effects on flower number. Daminozide application had not affected on the stomatal conductance. Application ofdaminozide at 500 mg L-1 given in triple application was found to be effective in producing short, compact plants with more flowers

Effects of pollination techniques and harvesting stage on the physico-chemical characteristics of jackfruit

Pollination techniques could affect fruit size, whereas optimal maturity stage during harvest could affect postharvest life and the eating quality of fruit. Therefore, the right pollination technique and timing to harvest fruit is an important factor in reducing postharvest losses. The objective of this study was to determine the physico-chemical changes of jackfruit harvested at four different maturity stages and produced from natural and assisted pollination. This study was conducted at a jackfruit commercial farm in Bukit Beruntung, Selangor, Malaysisa. For assisted pollination, the selected female inflorescences were covered with bags before anthesis. Hand pollination was performed by gently rubbing mature male inflorescences over the surface of receptive female inflorescences. For natural pollination, female inflorescences were left to develop into syncarps by themselves. Syncarps at the age of 12, 13, 14 and 15 weeks after anthesis (WAA) were used in this study. For each maturity stage, four syncarps were harvested and allowed to ripen naturally at 27±2 °C and 70−80% relative humidity until a sweet aroma was detected. Physico-chemical characteristics such as colour, firmness, pH, titratable acidity, β-carotene, lycopene content, sugars, organic acid content and antioxidant activity were evaluated. In this study, the pollination technique did not affect the eating quality of jackfruit flesh. However, the physico-chemical quality of jackfruit flesh was affected by ripening level and WAA. The initial stages of syncarp maturity, the L*, C* and ho values, remained unaffected. However, the L*, C* and ho decreased significantly from 14 WAA onwards when the syncarp rind turned fully yellow. This indicated that the rind and bulb colour became lighter and less intense with a green colour changing to yellow during ripening. Rind and flesh firmness decreased as ripening progressed due to cell wall modification and starch hydrolysis when ripening occurred. The β-carotene content of fleshy syncarps harvested at 14 and 15 WAA was higher than those harvested at 12 and 13 WAA. Sugar content such as glucose, fructose and sucrose increased as syncarps ripened. Total phenolic, flavonoid and antioxidant content were higher after syncarps ripened compared to before ripening. The ripe edible parts of jackfruit contain high levels of antioxidant and thereby signify the nutritional value of jackfruit for human health. In conclusion, harvesting stages affect the nutritional quality of jackfruit cv. Tekam Yellow, and it is recommended that the optimal harvesting stage of jackfruit is 14 WAA for local markets and 12 WAA for long-distance markets

Development of high yield and tomato yellow leaf curl virus TYLCV resistance using conventional and molecular approaches: a review

Tomato (Solanum lycopersicum L.) belonging to the family Solanaceae is the second most consumed and cultivated vegetable globally. Since the ancient time of its domestication, thousands of cultivated tomato varieties have been developed targeting an array of aspects. Among which breeding for yield and yield-related traits are mostly focused. Cultivated tomato is extremely genetically poor and hence it is a victim for several biotic and abiotic stresses. Among the biotic stresses, the impact of viral diseases is critical all over tomato cultivating areas. Improvement of tomato still largely rely on conventional methods worldwide while molecular approaches, particularly Marker Assisted Selection (MAS) has become popular across the globe as a fast, low cost and precise tool which is essential in present day plant breeding. In this review paper, breeding tomato for high yield and viral disease resistance, particularly to tomato yellow leaf curl virus disease (TYLCVD) using conventional and molecular approaches will be discussed. Lining up of this set of information will be useful to those who are interested in tomato variety development with high yielding and TYLCVD resistance

Genetic variability, heritability, and clustering pattern exploration of Bambara groundnut (Vigna subterranea L. Verdc) accessions for the perfection of yield and yield related traits

Bambara groundnut (Vigna subterranea L. Verdc.) is considered an emerging crop for the future and known as a crop for the new millennium. The core intention of this research work was to estimate the variation of landraces of Bambara groundnut considering their 14 qualitative and 27 numerical traits, to discover the best genotype fitted in Malaysia. The findings of the ANOVA observed a highly significant variation () for all the traits evaluated. There was a substantial variation (7.27 to 41.21%) coefficient value, and 14 out of the 27 numerical traits noted . Yield (kg/ha) disclosed positively strong to perfect high significant correlation ( to 1.00; ) with traits like fresh pod weight, dry pod weight, and dry seed weight. The topmost PCV and GCV values were estimated for biomass dry (41.09%) and fresh (40.53%) weight with high heritability (Hb) and genetic advance (GA) %, % and %, %, respectively. The topmost heritability was recorded for fresh pod weight (99.89%) followed by yield (99.75%) with genetic advance 67.95% and 62.03%, respectively. The traits with and suggested the least influenced by the environment as well as governed by the additive genes and direct selection for improvement of such traits can be beneficial. To estimate the genetic variability among accessions, the valuation of variance components, coefficients of variation, heritability, and genetic advance were calculated. To authenticate the genetic inequality, an unweighted pair group produced with arithmetic mean (UPGMA) and principal component analysis was executed based on their measurable traits that could be a steadfast method for judging the degree of diversity. Based on the UPGMA cluster analysis, constructed five distinct clusters and 44 accessions from clusters II and IV consider an elite type of genotypes that produce more than one ton yield per hectare land with desirable traits. This study exposed an extensive disparity among the landraces and the evidence on genetic relatives will be imperative in using the existing germplasm for Bambara groundnut varietal improvement. Moreover, this finding will be beneficial for breeders to choose the desirable numerical traits of V. subterranea in their future breeding program

DNA fingerprinting, fixation-index (Fst), and admixture mapping of selected Bambara groundnut (Vigna subterranea [L.] Verdc.) accessions using ISSR markers system

As a new crop in Malaysia, forty-four Bambara groundnut (Vigna subterranea L. verdc.) genotypes were sampled from eleven distinct populations of different origins to explore the genetic structure, genetic inconsistency, and fixation index. The Bambara groundnut, an African underutilized legume, has the capacity to boost food and nutrition security while simultaneously addressing environmental sustainability, food availability, and economic inequalities. A set of 32 ISSRs were screened out of 96 primers based on very sharp, clear, and reproducible bands which detected a total of 510 loci with an average of 97.64% polymorphism. The average calculated value of PIC = 0.243, RP = 5.30, H = 0.285, and MI = 0.675 representing the efficiency of primer set for genetic differentiation among the genotypes. The ISSR primers revealed the number of alleles (Na = 1.97), the effective number of alleles (Ne = 1.38), Nei's genetic diversity (h = 0.248), and a moderate level of gene flow (Nm = 2.26) across the genotypes studied. The estimated Shannon’s information index (I = 0.395) indicates a high level of genetic variation exists among the accessions. Based on Nei’s genetic dissimilarity a UPMGA phylogenetic tree was constructed and grouped the entire genotypes into 3 major clusters and 6 subclusters. PCA analysis revealed that first principal component extracted maximum variation (PC1 = 13.92%) than second principal component (PC2 = 12.59%). Bayesian model-based STRUCTURE analysis assembled the genotypes into 3 (best ΔK = 3) genetic groups. The fixation-index (Fst) analysis narrated a very great genetic diversity (Fst = 0.19 to 0.40) exists within the accessions of these 3 clusters. This investigation specifies the effectiveness of the ISSR primers system for the molecular portrayal of V. subterranea genotypes that could be used for genetic diversity valuation, detection, and tagging of potential genotypes with quick, precise, and authentic measures for this crop improvement through effective breeding schemes

Development of anthracnose disease resistance and heat tolerance chili through conventional breeding and molecular approaches: a review

Chili (Capsicum annuum L.) is the popular spicy vegetable crops belonging to family Solanaceae. Chili peppers are known for their pungency characteristic due to the presence of capsaicinoids that classifies them into hot or sweet pepper. Chili is used as spices, folk remedies for diseases, vegetables, and coloring agent showing a diverse role in human’s life. However, its production is hampered by different biotic stress and abiotic factors. Similarly, the unavailability of high yielding varieties, high temperature, and disease incidence, particularly, anthracnose disease, are the major constraints responsible for the low production of chili pepper. The advents of molecular markers, advancement in quantitative trait loci by classical genetic analysis, and conventional breeding have shown the number of genes for many important and major traits. While the newly developed genotyping technologies and next generation sequencing have led to the discovery of molecular basis for economic important characters in the chili genome and generate large scale data for genomic resources. Based on this background, this review summarizes progress in the development of anthracnose disease-resistant and heat-tolerant chili genotypes through conventional breeding and molecular approaches. This review would help plant breeders in understanding the phenotypic and genetic make-up of capsicum genotypes and provides opportunities for pyramiding two respected genes with the help of diversified phenotypic and molecular marker evaluation

Determination of lethal (LD) and growth reduction (GR)doses on acute and chronic gamma- irradiated Bambara groundnut [Vigna subterranea (L.) Verdc.]varieties

Bambara groundnut is a highly nutritious underutilized legume with enormous potential to sustain food security in resource-poor countries. However, its potential for improvement through conventional breeding (< 2% success rate) limitation due to the nature of the flowers. Thus, the most viable method of improving this crop is by creating genetic variability through induced mutagenesis. The present study was conducted to evaluate the radiosensitivity of two Bambara groundnut varieties irradiated with acute and chronic gamma irradiations to determine the lethal dose (LD) and growth reduction dose (GR). Healthy seeds of both varieties were exposed to acute gamma irradiation using Cesium-137 at 0, 25, 50, 75, 100, 125, 150, 175, 200, 250, and 300 Gy. For chronic irradiation, two-week-old seedlings of the two genotypes were exposed to accumulated doses of 0, 8.52, 17.04, 35.56, 34.09, 42.61, 59.65, 93.74, 144.87, 255.64, and 570.94 Gy, respectively, in Gamma Green House (GGH) for 60 days. The result from the variance analysis indicated highly significant differences (P < 0.01) for all evaluated traits except for internode length. A linear regression model was developed to determine the mean LD and GR of both genotypes. The established lethal doses (LD25, 50, 75) for acute gamma irradiation on Ex-Sokoto variety were 75, 160, and 250 Gy while 68, 148, and 227 Gy were recorded for Karo variety, respectively. For chronic irradiation, the established growth reduction doses for Ex-Sokoto were 47, 250, and 444 Gy, whereas 70, 264, and 452 Gy were observed in Karo. Variations were observed between the gamma-irradiated genotypes and the methods of irradiations. Generally, the growth, development, and survival rate of Bambara groundnut increase with a decrease in gamma-irradiation doses. The established LD and GR doses from this study can be utilized in large-scale mutagenesis breeding programs for generating a wide range of mutants in Bambara groundnut

Effect of organic and inorganic fertilizer on the growth and yield components of traditional and improved rice (Oryza sativa L.) genotypes in Malaysia

Rice is the most important staple cereal human nutrition and consumed by 75% of the global population. Rice plants need a supply of essential nutrients for their optimal growth. Rice production has increased tremendously in Malaysia insensitive irrigation and the use of inorganic fertilizers and pesticides. However, the effect of using inorganic fertilizers resulted in contamination of ground water and decreased the productivity of soil, which in turn affected the rice production in the long term. The use of organic manure may help to regain the soil health, but that is insufficient for providing the essential nutrients to achieve optimal growth. Therefore, the use of organic manure combined with inorganic fertilizers is applied to obtain optimum yields. This study aims to test the effect of organic and inorganic fertilizers on the growth and yield components of 65 rice genotypes. The pot experiment was conducted at the net house on field 10, University Putra Malaysia, UPM, Malaysia, during the period of February to June 2019 and August to December 2019 in a randomized complete block design (RCBD) with three replications. There were three treatment combinations viz. T1: 5 t ha−1 chicken manure (CM), T2: 2.5 t ha−1 CM + 50% CFRR, T3: 100% (150 N: 60 P2O5: 60 K2O kg ha−1) and chemical fertilizer recommended rate (CFRR). Grain and straw samples were collected for chemical analysis, and physical parameters were measured at the harvest stage. Results showed that most of the growth and yield components were significantly influenced due to the application of organic manure with chemical fertilizer. The application of chemical fertilizer alone or in combination with organic manure resulted in a significant increase in growth, yield component traits, and nutrient content (N, P, and K) of all rice genotypes. Treatment of 2.5 t ha−1 CM + 50% CFRR as well as 100% CFRR showed a better performance than the other treatments. It was observed that the yield of rice genotypes can be increased substantially with the judicious application of organic manure with chemical fertilizer. The benefits of the mixed fertilization (organic + inorganic) were not only the crop yields but also the promotion of soil health, the reduction of chemical fertilizer input, etc

A review on gene pyramiding of agronomic, biotic and abiotic traits in rice variety development

Rice Oryza sativa L is a staple food crop, and its seeds are the most important component part of the agronomic trait of the cereal crop, rich in nutrient and of economic value to human and even livestock. But, it is often threatened by various abiotic and biotic conditions that reduce the yield, because of high incidences of infectious disease agents and non-pathogenic conditions respectively. Pyramiding of the requisite resistance and tolerance genes into single elite high yielding variety of rice, confers wider spectrum of stress management, resulting to development of single multiline variety of rice. Marker-assisted selection utilizes DNA marker-linked primers for blast resistant gene (RM8225;Piz, RM6836;Piz, Pi2,Pi9), bacteria leaf blight (RM224; Xa-4, RM122;xa-5, RG136; xa-13, RM21;Xa-21) and drought tolerance (RM236;qDTY2.2, RM520;qDTY3.1, RM511;qDTY12.1) in pedigree, backcross and recurrent selection breeding methods. The objectives are to create awareness on the environmental safety of host-resistance, significance of single multiline resistance variety, effect of the interaction of stress conditions and associated simple sequence repeat (SSR) linked markers

Evaluation of inherited resistance genes of bacterial leaf blight, blast and drought tolerance in improved rice lines

Improved rice lines were developed frome three parents with the resistance or tolerance to bacterial leaf blight, blast and drought stress, respectively, using single-, double- and three-way crosses. The improved lines were assessed for agro-morphological and yield traits under non-drought stress (NS) and reproductive-stage drought stress (RS) treatments. The mean comparison of traits measured between parent plants and progenies (improved lines) were similar, and there were significant and non-significant differences among the parents and improved lines (genotypes) under NS and RS. Smilarly, there was significant and non-significant differences in the interaction among both parent varieties and improved lines for NS and RS. Cluster and 3D-model of principal component analysis did not generate categorical clusters according to crossing methods, and there were no exclusive crossing method inclined variations under the treatments. The improved lines were high-yielding, disease resistant, and drought-tolerant compared with their parents. All the crossing methods were good for this crop improvement program without preference to any, despite the number of genes introgressed