广东省149个油茶品种（系）对炭疽病的抗性及其病原菌鉴定

为明确广东省油茶品种（系）对炭疽病的抗性及引起油茶炭疽病的病原菌种类,对广东省肇庆市、广州市和韶关市的149个油茶品种（系）进行田间抗性调查,从发病组织中分离纯化致病菌,观察菌株形态学特征,并结合3-磷酸甘油醛脱氢酶（glyceraldehyde-3-phosphate dehydrogenase,GAPDH）基因扩增序列进行分子生物学鉴定。结果显示,有93.29%的油茶品种（系）发生炭疽病,3个调查地油茶炭疽病的平均发病率为18.86%~24.25%,较抗病的油茶品种（系）占调查总数的53.02%,感病油茶品种（系）占调查总数的46.98%。其中,海南3号、长林400号和湘林89号等10个品种（系）表现为近免疫,揭阳5号、桂14号和湘林350号等16个品种（系）表现为高抗,赣5190号、湘林27号和岑软11号等53个品种（系）表现为中抗,赣兴46号、赣州S4号和赣州R10号等36个品种（系）表现为中感,岑软11-3000号、长林53号和湘林67号等34个品种（系）表现为高感,其中岑软11-19号发病率高达65.00%。共分离获得油茶炭疽病致病菌25株,结合形态学特征和基于GAPDH序列的系统发育树分析,将其中24株鉴定为果生炭疽菌Colletotrichum fructicola,1株鉴定为为暹罗炭疽菌C. siamense。筛选的油茶抗病品种（系）可作为广东省油茶良种选育材料,且该省油茶炭疽病主要由果生炭疽菌引起。     

Optical properties of novel pyrene fluoric chemosensor toward fluoride anions

The novel pyrene based dye sensor was designed and synthesized through the reaction between pyrene-1-carboxaldehyde and 4-phenylthiosemicarbazide. This dye sensor showed selectivity and sensitivity binding properties toward F? ion with showing absorption and emission changes in DMSO. These optical properties were investigated by using UV-vis spectrometer and emission spectrophotometer. In addition, electron distributions and HOMO/LUMO values of this dye sensor were simulated and calculated with theoretical calculations of Material Studio 4.3.     

Interaction of source-plant age and shoot ringing on rooting of cashew (Anacardium occidentale L.) cuttings

Summary

IBA-treated cuttings rooted only when prepared fom bark-ringed shoots. The response to ringing declined with increasing age of the tree. However, on marcotting, the ringed shoots of four year old trees showed more and earlier rooting.     

Effect of storage temperature on ripening and quality of custard apple (Annona squamosa L.) fruits

Summary

The effect of storage temperature on ripening, shelf life and chemical composition of custard apple (Annona squamosa L.) fruits stored at 10,15,20 and 25°C was studied. The safe range of storage temperature was found to be between 15 and 20°C, with maximum shelf life at 15°C. The ripening of fruits was observed on days 4, 6 and 9 of storage at 25,20, and 15°C respectively. The colour of the pulp, texture, taste and flavour of ripe fruits held at 25 and 20°C were superior followed by fruits stored at 15°C. At 10°C, the fruits became hard with surface blackening, messy pulp and less sweetness. The major changes during ripening were a continuous decrease in fruit firmness and starch content and a continuous increase in TSS and sugars, the changes being more rapid at 25 and 20°C than at 15 and 10°C. The acidity and ascorbic acid contents increased slightly during the initial stages of ripening followed by a decline, in the fruits stored at different temperatures. Custard apple fruits stored at 25 and 20^CC had a clear climacteric peak whereas those stored at 15 and 10°C did not show any distinct rise in respiration rate. Ethylene peak (2.40 µl kg^–1 h^–1) coincided with the respiratory climacteric at 25^CC storage, corresponding with the peaks in TSS, sugars, ascorbic acid and acidity.     

Biochars influence sweet‐potato yield and nutrient uptake in tropical Papua New Guinea

Currently, the biomass of an invasive and obnoxious weed, kunai grass (Imperata cylindrica), is uncontrollably burnt in Papua New Guinea in subsistence farming systems resulting in unwarranted negative environmental consequences. We explored the possibility of sustainable utilization of biochar produced from the weed biomass along with a standard feedstock‐rice husk (Oryza sativa). Biochars were produced with lab‐scale pyrolysis at 550°C, characterized for chemical properties and plant nutrient composition. Further, agronomic efficacy of soil incorporation of biochars (5 t ha^?1) or co‐applied with mineral fertilizers (100, 11, and 62 kg ha^?1 N, P, K, respectively) was tested for sweet potato (Ipomoea batatas L. Lam) in a field experiment. The two biochars differed significantly (P < 5%) with respect to recovery from the feedstocks, chemical characters and nutrient composition. Kunai grass biochar was poorer in nutrients (< 1%) with distinctly alkaline pH and higher electrical conductivity. Biochar amendment to soil showed significant (P < 5%) improvement of soil moisture, while co‐application of biochars along with mineral fertilizers showed soil moisture decrease. Biochar amendment improved the growth parameters and total tuber yield of sweet potato by about 20%, while co‐application with mineral fertilizers augmented total tuber yield by 100% and above‐ground biomass yields by > 75%. Besides, improving agronomic performance of sweet potato crop, co‐application of biochars with mineral fertilizers enhanced uptake of N, P, K, Ca, Mg, and S. Production and utilization of biochar in sweet‐potato production could offer an efficient means of disposing biomass of kunai grass with concomitant productivity improvement in Papua New Guinea.     

X-ray diffraction patterns of transfer RNA consistent with the presence of short parallel helices in the molecule

X-ray diffraction data of yeast formylmethionine transfer RNA, Escherichia coli phenylalanine transfer RNA, and Escherichia coli arginine transfer RNA single crystals are compared with the Fourier transform of a helix. The results are consistent with the presence of short parallel double helical segments in the transfer RNA molecules.     

长江中下游中籼迟熟A组水稻品种区域试验结果分析

为鉴定评价福建省三明市水稻联合体成员新选育的中籼迟熟品种在长江中下游稻区的丰产性、稳定性、适应性、抗逆性、米质及其它重要性状表现。2019年三明市水稻联合体开展长江中下游中籼迟熟组水稻新品种区域试验,参试品种13个,其中续试并生产试验品种2个,续试品种2个,新参试品种9个。试验结果,遂两优164可以申报审定,两优8699、创优9708生产试验,鸿两优6363、两优1899、智两优6522续试和生产试验,禾两优6868、广两优366续试。     

Nutrient composition and biological evaluation of mesta (Hibiscus sabdariffa) seeds

Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.     

Simple multiresidue method for monitoring of trimethoprim and sulfonamide residues in buffalo meat by high-performance liquid chromatography

A simple, specific, and rapid analytical method for the determination of trimethoprim (TMP) and three sulfonamide (SA) antimicrobial drug residues in buffalo meat is developed and validated. This method is based on a solid-phase extraction technique followed by high-performance liquid chromatography (HPLC)-photodiode array (PDA) detection. Target compounds were extracted from the meat by acetonitrile and water, cleaned up on a Bond Elute C 18 cartridge column, and separated on a RP-C 18 column during HPLC analysis. Acetonitrile along with water appears to be an excellent extractant as recovery of the analytes at maximum residues levels (MRLs) in spiked sample was in the range of 75-108%, with coefficient of variations (CVs) ranging between 1.34 and 22%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.031 and 0.062 microg/g, respectively, for all of the compounds. Intra- and interday assay precisions of the method at 0.125 microg/g concentrations for any drug ranged between 3 and 4%. The linearities of the TMP, sulfadimidine (SDM), sulfadoxine (SDO), and sulfamethoxazole (SMX) were 0.9989, 0.9999, 0.9998, and 0.9997, respectively. For robustness, the analytical method was applied to 122 buffalo meat samples obtained from export meat processing plants.