Response of rice to inoculation with genetic engineered strains of associative diazotrophs

Enhancement of nitrogen fixation in the rhizo-sphere of cereals has attracted a wide interestin biological and agricultural research,insteadof chemicals,for supplying higher plants withcombined nitrogen.Bacteria in association withrice plant.s were sensitive to the surroundingfactors in the soil,such as NH~+ or O,whichrepressed associative nitrogen fixation between

Microsatellite analysis of variation among wild, domesticated, and genetically improved populations of blunt snout bream （Megalobrama amblycephala）

In the present study, the genetic diversity of one selected strain （Pujiang No. 1）, two domesticated populations （GA and HX） and four wild populations （LZ, YN, SS and JL） of blunt snout bream （Megalobrama amblycephala） was analyzed using 17 microsatellite markers. The results showed that an average of 4.88-7.65 number of alleles （A）; an average of 3.20-5.33 effective alleles （Ne）; average observed beterozygosity （Ho） of 0.6985-0.9044; average expected beterozygosity （He） of 0.6501--0.7805; and the average polymorphism information content （PIC） at 0.5706-0.7226. Pairwise FST value between populations ranged from 0.0307-0.1451, and Nei＇s standard genetic distance between populations was 0.0938-0.4524. The expected heterozygosities in the domesticated populations （GA and HX） were significantly lower than those found in three wild populations （LZ, SS and JL）, but no difference was detected when compared with the wild YN population. Likewise, no difference was found between the four wild populations or two domesticated populations. The expected heterozygosity in Pujiang No. 1 was higher than the two domesticated populations and lower than the four wild populations. Regarding pairwise Fsr value between populations, permutation test P-values were significant between the GA, HX and PJ populations, but not between the four wild populations. These results showed that the expected beterozygosity in the selected strain of blunt snout bream, after seven generations of selective breeding, was lower than that of wild populations, but this strain retains higher levels of genetic diversity than domesticated populations. The genetic differences and differentiation amongst wild populations, domesticated populations and the genetically improved strain of blunt snout bream will provide important conservation criteria and guide the utilization of germplasm resources.

CRISPR-based genetic control strategies for insect pests

Genetic control strategies such as the sterile insect technique have successfully fought insect pests worldwide. The CRISPR(clustered regularly interspaced short palindromic repeats) technology, together with high-quality genomic resources obtained in more and more species, greatly facilitates the development of novel genetic control insect strains that can be used in area-wide and species-specific pest control programs. Here, we review the research progress towards state-of-art CRISPR-based genetic control strategies, including gene drive, sex ratio distortion, CRISPRengineered genetic sexing strains, and precision-guided sterile insect technique. These strategies’ working mechanisms,potential resistance development mechanisms, and regulations are illustrated and discussed. In addition, recent developments such as stacked and conditional systems are introduced. We envision that the advances in genetic technology will continue to be one of the driving forces for developing the next generation of pest control strategies.

Design of temperature insensitive in vivo strain sensor using multilayer single mode optical fiber

Bone strain measurement is a case of interest and demanding task for osteogenic adaption responses. In this paper, a novel biocompatible optical sensor for the bone axial strain measurement was proposed. In case modern multilayer single mode WII type optical fibers are well designed, they exhibit superior characteristics compared to conventional metal strain gauges （SGs）. Furthermore, they could be strong competitors for SGs based on fiber Bragg grating （FBG） devices. In this study, mode field diameter （MFD） was selected as the indirect parameter for sensing task, which was totally a new approach. The strain sensitivity of 70.7733 pm/με was obtained. Moreover, temperature sensitivity was -3.0031 x 10-6 pm/℃, which was negligible and removed the temperature compensation complexity for the sensor structure presented. The satisfactory property achieved for the designed sensor is as a result of multilayer fiber＇s complicated structure as well as the design procedure based on evolutionary genetic algorithm （GA）. In addition, the sensor demonstrated a reliable performance as its sensitivity was independent of the magnitude of the applied load.