Effects of AG1 and AG2 QTLs on Nonstructural Carbohydrate and Seed Management Options for Rice Seedling Growth and Establishment under Flooding Stress

Rice (Oryza sativa) plants acquired excess photosynthates in the form of nonstructural carbohydrates (NSCs) in their stems and grain. Despite keen interest in rice NSC, the dynamics of NSC accumulation, translocation and re-accumulation have not yet been well investigated. AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds. Here we conducted three experiments, greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice (DSR) system, using elite lines incorporating AG1, AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On (AG1) and Ma-Zhan Red (AG2). In germinating seedlings, soluble sugars increased, while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil. Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage. But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017. Plant survival rate was positively correlated with the stem NSC at the early vegetative stage (21 days after sowing), and stem NSC was positively associated with plant height at different growth stages. Among the tested seeding rate, the most suitable seeding rate, 4 g/m² with shallow burial depth (0.5 cm), resulted in better seedling establishment, relatively higher seedling vigor index and higher leaf area index under flooding in DSR system. Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate, germination rate, and growth and biomass production.     

Clostridium bifermentans and C. subterminale are associated with kiwifruit vine decline,known as moria,in Italy

Since 2012, a new pathogenic syndrome has frequently been observed in many areas of kiwifruit cultivation in Italy. The main symptoms include an initial withering of the leaves followed by a total and sudden collapse of plants, mainly occurring during summer. The withered leaves fall and the main and secondary feeder roots appear rotten, sometimes showing a reddish-brown discoloration. The disease, that affects both the green and yellow-fleshed cultivars, has been called kiwifruit vine decline and is locally known as moria. The syndrome has been found consistently associated with soil waterlogging, which frequently occurs either after the traditional agronomical practice of irrigating orchards through surface irrigation or after very heavy rainfall. So far, the role played by bacteria in this syndrome has not been investigated. In the present study, Clostridium spp. were isolated from both rotten roots and soils obtained from Italian kiwifruit orchards affected by the syndrome, indicating for the first time that anaerobic bacteria are able to cause damage to woody crops. C. bifermentans and C. subterminale incited symptoms in kiwifruit in both in vivo and in vitro pathogenicity tests. Soil waterlogging seems to potentially favour colonization of kiwifruit roots by anaerobic bacteria, probably because saturation of the soil can facilitate proliferation and persistence of these bacteria during long periods of the vegetative growth of the crop. The occurrence of anaerobic bacteria does not exclude the possibility that other microorganisms can play additional/synergic role(s) in causing the kiwifruit vine decline.     

Antibacterial activity of the essential oil from Aristolochia indica

The essential oil of Aristolochia indica, containing beta-caryophyllene and alpha-humulene as major constituents, was found to show a moderate antibacterial activity.     

Molecular simulations of Taxawallin I inside classical taxol binding site of β-tubulin

A new taxoid Taxawallin I (1) along with two known taxoids (2-3) were isolated from methanolic bark extract of Taxus wallichiana Zucc. Structural characterization was confirmed by mass and NMR spectral techniques. Taxawallin I exhibited significant in-vitro anticancer activity against HepG2, A498, NCI-H226 and MDR 2780AD cancer lines. Tubulin binding assay was performed to assess its tubulin binding activity. Molecular docking analysis was performed to study the potential binding mode inside the taxol binding site of β-tubulin.     

Changes in enzyme activities,soluble sugars and phenols during in vitro adventitious shoot regeneration from leaflet explants of <Emphasis Type="Italic">Albizia procera</Emphasis> (Roxb.) Benth

Changes in nitrate reductase, i.e. NR (E.C. 1.7.1.1) activity, peroxidase (E.C. 1.11.1.14) activity, soluble sugars and phenols were monitored at various time intervals from day 0 to 60 during in vitro adventitious shoot regeneration from leaflet explants of Albizia procera (Roxb.) Benth. The explants were incubated on semi-solid Murashige and Skoog medium supplemented with 2.6 g l^?1 Phytagel^®, 2.5% sucrose, 10 μM BAP, 1 μM NAA and 15 μM AgNO₃. NR activity, soluble sugars and phenols exhibited initial sharp rise on around day 20 followed by steep decline on day 25, whereas peroxidase activity peaked on day 50, highlighting significance of early input of nitrogen and energy and late emergence of lignification process for cellular differentiation and organization into adventitious shoot primordia. Morpho-anatomical changes in leaflets at various stages of in vitro adventitious shoot formation also followed the endogenous biochemical pattern.     

Using leaf tip necrosis as a phenotypic marker to predict the presence of durable rust resistance gene pair <Emphasis Type="Italic">Lr34</Emphasis>/<Emphasis Type="Italic">Yr18</Emphasis> in wheat

Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait.     

Influence of the species and geographical location on volatile composition of Spanish oak wood (Quercus petraea Liebl. and Quercus robur L.)

The influence of the species and geographical origin on the volatile composition of wood samples from 80 Spanish oaks (55 Quercus petraea Liebl. and 25 Quercus robur L.) has been studied. Oak volatile components were isolated by simultaneous distillation-extraction and analyzed by gas chromatography-mass spectrometry. cis- and trans-beta-methyl-gamma-octalactones were the main constituents, the cis stereoisomer being predominant. Other important volatile components were furfural, 5-methylfurfural, guaiacol, eugenol, vanillin, or syringaldehyde. The main differences were established between species, Quercus petraea being significantly richer in volatile compounds than Quercus robur; however, the variability found among trees was high. Differences among geographical provenances were much less important than those found between species.     

Hydroxymethanesulphinate salts and related decomposition products in wastewater

Hydroxymethanesulphinate (HMS) and its decomposition products such as HCHO, Zn and sulphites can be determined quantitatively in each other's presence by a polarographic method. In the alkaline medium it is possible to have well defined and separated waves relative to the oxidation of HMS ion and to the reduction of HCHO and zincate ion. The quantitative determination of these compounds is carried out with standard addition methods since the concentration-current relationship is linear. The SO₂ is determined in HClO₄ 0.1 M and in the same sample it is possible to determine even HMS, HCHO and Zn after addition of NaOH up to 0.1 M. Moreover, a method of indirect determination of HMS is herein described. This is based on the determination of HCHO released by means of a weak oxidation of HMS which is stoichiometrically proportional to the total HMS. The method is sensitive and is made specific for such types of wastewater which come from textile industries.