Influence of some hardwood barks as soil amendments onRotylenchulus reniformis reproduction and growth response of sunflower

Four hardwood barks (HWB) i. e.Acacia arabica (AA),Ficus sycomorus (FS),Morus alba (MA) andZiziphus spinachristi (ZS) were tried as soil amendments at 0.5, 1.0 and 1.5% rates w/w for control ofRotylenchulus reniformis and improvement of cv. Giza 1 sunflower growth under greenhouse conditions. All HWB with various concentrations significantly (P≤0.01) reduced numbers of larvae in soil, both females and eggmasses on roots, total final nematode population as well as the nematode build-up as compared to control. 1.5% rate of ZS, AA and MA barks were most effective in reducing numbers of larvae in soil, total final nematode population and the nematode build-up. Also, 1.5% rate of each of FS and AA barks were most effective in reducing numbers of females or eggmasses, respectively. On the other hand, the least reduction in the previous nematode stages and rate of build-up was observed with 0.5% dose of FS bark. Shoot weights were increased significantly with both of 1.0% and 1.5% doses of each of FS and ZS barks and only with 1.5% dose of MA bark. Both shoot lengths and root weights increased significantly with 1.5% dose of all HWB or with 1.0% dose of each of AA and ZS barks as compared to control. No significant increase in root lengths was observed. Generally, there were positive significant correlations between doses of HWB, each of the reductions in the previous nematode stages and increases in sunflower growth criteria.     

Impact of glucosinolate in relation to leafminer,Liriomyza brassicae Riley (Diptera: Agromyzidae) infestation in crucifers

Eight species belonging to the Family Cruciferae were classified to lafminer resistant, tolerant and susceptible on the basis of leafminer infestation. They were analyzed for the glucosinolate content and correlated with leafminer infestation. Total glucosinolate content in general and sinigrin content in particular appeared to have the ability to repel the attack ofLiriomyza brassicae, while gluconapin appeared to attract them. The percentage of infestation, the number of mines and the number of living larvae were estimated for evaluating the glucosinolate efficacy againstL. brassicae on cabbage.     

Influence of silicon on growth,yield, and lodging resistance of MR219, a lowland rice of Malaysia

Lodging has limited yield and potential of increasing yield in rice. Lodging could be minimized by increasing the mechanical or physical strength of the rice culm. Silicon (Si) is associated with sturdiness and rigidity. Therefore, the objectives of this experiment were to evaluate the effects and optimum rate of Si application to improve yield, growth, and lodging resistance of MR219, a popular rice variety in Malaysia. Si, in the form of fertilizer, was applied at the onset of reproductive stage as topdressing. All Si-treated plants showed an increase in number of tillers, number of spikelets per panicle, number of effective tillers, percentage of filled spikelets, and weight per panicle in Si-treated plants as compared to control. Lodging resistance was higher in plants treated with Si as shown by bending parameters. Si-treated plants showed significant increase in flag leaf area, chlorophyll content, and Si content.     

X-ray diffraction studies of poly(aryl ether ether ketone) fibers with different degrees of crystallinity and orientation

A selection of commercially available poly(ethylene terephthalate) fibers with different degrees of molecular alignment and crystallinity have been investigated utilizing a wide range of techniques including optical microscopy, infrared spectroscopy together with thermal and wide-angle X-ray diffraction techniques. Annealing experiments showed increased molecular alignment and crystallinity as shown by the increased values of birefringence and melting enthalpies. Crystallinity values determined from thermal analysis, density, unpolarized infrared spectroscopy and X-ray diffraction are compared and discussed in terms of the inherent capabilities and limitations of each measurement technique. The birefringence and refractive index values obtained from optical microscopy are found to decrease with increasing wavelength of light used in the experiments. The wide-angle X-ray diffraction analysis shows that the samples with relatively low orientation possess oriented non-crystalline array of chains whereas those with high molecular orientation possess well defined and oriented crystalline array of chains along the fiber axis direction. X-ray analysis showed increasing crystallite size trend with increasing molecular orientation. SEM images showed micro-cracks on low oriented fiber surfaces becoming smooth on highly oriented fiber surfaces. Excellent bending characteristics were observed with knotted fibers implying relatively easy fabric formation.     

Effects of three carbohydrate sources on water quality,water consumption,bacterial count,growth and muscle quality of Nile tilapia (Oreochromis niloticus) in a biofloc system

This study compared the effect of three sources of carbohydrates: sugar, wheat and malt flours, on water quality, water consumption, bacterial load, growth and flesh quality of Nile tilapia. Adults (120.6 ± 0.64 g) were stocked in 1.2‐m³ fibreglass tanks at a rate of 25 fish/m³. Carbohydrates were added to the biofloc tanks at a C:N ratio of 20:1. Water flow in the non‐biofloc control tanks was adjusted to 0.6 L/day. The 105‐day experiment was conducted in triplicates. Results showed that biofloc treatments (BFT) with zero water exchange had significantly higher mean total ammonia, nitrites, nitrates, alkalinity, total suspended solids and lower pH than the control treatment. The sugar BFT had the highest floc volume. Growth parameters and feed conversion ratio did not differ significantly among treatments. However, tilapia in the malt flour and control treatments had close values. Gross fish yield was higher (p < .05) in the control than the BFT treatments. Water consumption/kg tilapia produced in the control was 42 times higher than the BFT groups. Protozoa dominated the biofloc biota, and wheat flour was the best in harbouring higher bacterial populations in the gut. Protein content and ∑n‐3 fatty acids were highest in the wheat flour biofloc, while malt flour biofloc had the highest lipids. The sugar biofloc had the highest n‐3/n‐6 ratio. Tilapia muscles in the malt flour and control treatments had the highest protein and lipid contents respectively. Tilapia muscles in the wheat flour BFT had the highest ∑n‐3 fatty acids and n‐3/n‐6 ratio. It can be concluded that farming tilapia in BFT using malt or wheat flours as carbon sources is more economical in saving great amount of water with minimal discharge of pollutants without affecting tilapia growth or flesh quality.     

Triploid Induction of Green Tiger Shrimp,Penaeus semisulcatus (De Haan, 1844) Using Temperature and Chemical Shock

Triploidy in fertilized eggs of Penaeus semisulcatus was induced by temperature and chemical shocks. The eggs, which were obtained from the shrimp broodstock maintained at 29 C, were exposed to cold temperature (8, 10, 12, and 14 C) and 6‐dimetiloaminopurine (6‐DMAP) concentrations (100, 150, 200, and 250 μM) for different durations (4, 6, and 8 min) 9 min after spawning was detected. While the highest triploidy rate of 49.7 ± 4.5% was obtained with a 200 μM 6‐DMAP concentration for a duration of 8 min, the best mean triploidy rate of 45.5 ± 2.8% for cold shock was obtained at a temperature of 10 C for a duration of 8 min. Temperature and 6‐DMAP concentration did not have significant effect on triploidy rate (P > 0.05) but shock duration had significant effect on triploidy rate for individual cold temperature shock or 6‐DMAP chemical shock (P < 0.05). Although longer durations of shock agent increased the rates of triploid induction, they generally had an adverse effect on hatching rates in the study.     

Assessing the utility of ALOS PALSAR and SPOT 4 to predict timber volumes in even-aged Eucalyptus plantations located in Zululand,South Africa

In commercial forestry, regular terrestrial enumerations of the growing stock are required for the valuation, sustain-able management and planning of current and future timber supplies. In this study we examined whether the combination of synthetic aperture radar (ALOS PALSAR) and optical satellite (SPOT 4) image data can accurately predict the timber volume of even-aged Eucalyptus plantations located in South Africa. Results from this study show that the combination of ALOS PALSAR and SPOT 4 produces a R ² value of 0.68 for the planted model, whereas the coppiced model produced a R ² value of 0.55. However, by including stand age as an independent variable in the stepwise model, there was a 15% improvement for the planted model, whereas the coppiced model produced a 27% improvement. The final model developed in this study produced a R ² value of 0.83 and a RMSE of 31.71?m³ ha?1 for planted stands, whereas the model for coppiced stands produced a R ² value of 0.82 and a RMSE of 27.70?m³ ha?1. As it is not practical or financially feasible for commercial forestry companies to carry out terrestrial enumerations for all plantations on an annual basis, the model developed in this study presents an alternative and accurate method to calculate timber volume for even-aged Eucalyptus plantations.     

Molecular confirmation of candidate Hsp70 gene associated with heat tolerance in BC3F2 advanced backcross lines and their phenotypic resemblance with recurrent chilli Kulai

ABSTRACT

Domestic production of chilli in Malaysia is insufficient which accounted for 52% self-sufficiency level. Poor performance of local varieties under high temperatures above 42°C is one of the major factors affecting chilli production. This study was conducted with the objective of introgress heat-tolerant gene (Hsps) from AVPP0702 donor into Kulai using marker-assisted backcrossing. A total of 68 SSR markers, including Hsp linked markers that showed polymorphism between the parents were used to assess the generation of backcrossing; BC1F1, BC2F1, BC3F1 and BC3F2 and the average RPG percentage of the recurrent parent was found to be 81, 90, 95 and 97%, respectively. The pattern of Hsp expression in the backcross generations was similar to the donor parent (upregulated with more than 4-fold increase). Twelve improved heat tolerant chilli lines were developed. Most of the morphological and agronomical traits were recovered in the selected improved heat-tolerant genotypes from Kulai such as plant height, number of days to 50% flowering, number of fruits, fruit length and total fruit yield per plant. Improved high-yielding heat-tolerant chilli lines showed tolerance to high temperature as well as did not express any negative effect on agronomic traits in comparison with Kulai variety.     

Inheritance of tolerance to leaf iron deficiency chlorosis in tomato

By using two tomato genotypes, 227/1 (Fe chlorosis susceptible) and Roza (Fe chlorosis tolerant), and their reciprocal F₁, F₂ and BC₁ generations, the inheritance of tolerance to leaf Fe deficiency chlorosis of Roza was studied. Plants were grown in a nutrient solution and subjected to 2.0 × 10^–6 M Fe EDDHA and 10 mM NaHCO₃ to induce Fe deficiency stress by stabilization of pH to 7.8–8.2. A rating scale of 1–3 for chlorophyll was used and both monogenic and polygenic inheritance hypotheses were tested. Better responses to Fe deficiency, as measured by SPAD meter values, were obtained from the cross Roza × 227/1 than from the reciprocal cross. Data from F₂ and BC₁ suggest Fe chlorosis tolerance of Roza is to be controlled by polygenic loci with a relatively high additive effect.