Common walnut (Juglans regia L.) is an economically important hardwood tree species cultivated worldwide for its high quality wood and edible nuts. It is generally accepted that after the last glaciation J. regia survived and grew in almost completely isolated stands in Asia, and that ancient humans dispersed walnuts across Asia and into new habitats via trade and cultural expansion. The history of common walnut in China is a matter of debate, however. We estimated the genetic diversity and spatial genetic structure of 31 walnut populations sampled across its Chinese range using 22 microsatellite markers (13 neutral and 9 non-neutral). Using historical data and population genetic analysis, including approximate Bayesian analysis (ABC), we reconstructed the demographic history of J. regia in China. The genetic data indicated the likely presence of J. regia in glacial refugia in the Xinjiang province (Northwest China), Northeastern China (Beijing, Shandong, and Changbai Mountains), Central China (Qinling and Baishan Mountains and Xi’an), and Southwestern China (Tibet, Yunnan, Guizhou, and Sichuan provinces). Based on DIY-ABC analysis, we identified three ancient lineages of J. regia in China. Two lineages (subpopulation A and subpopulation B+C) diverged about 2.79 Mya, while Southwestern China, and Qinling and Baishan Mountains lineages diverged during the Quaternary glaciations (about 1.13 Mya). Remnants of these once-distinct genetic clusters of J. regia may warrant ecological management if they are to be retained as in situ resources. A population size expansion in Northeastern China was detected in the last five centuries. The present distribution of walnut in China resulted from the combined effects of expansion/contraction from multiple refugia after the Last Glacial Maximum and later human exploitation.

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The common walnut (Juglans regia L.) and iron walnut (J. sigillata Dode) are well-known economically important species cultivated for their edible nuts, high-quality wood, and medicinal properties and display a sympatric distribution in southwestern China. However, detailed research on the genetic diversity and introgression of these two closely related walnut species, especially in southwestern China, are lacking. In this study, we analyzed a total of 506 individuals from 28 populations of J. regia and J. sigillata using 25 EST-SSR markers to determine if their gene introgression was related to sympatric distribution. In addition, we compared the genetic diversity estimates between them. Our results indicated that all J. regia populations possess slightly higher genetic diversity than J. sigillata populations. The Geostatistical IDW technique (HO, PPL, NA and PrA) revealed that northern Yunnan and Guizhou provinces had high genetic diversity for J. regia while the northwestern Yunnan province had high genetic diversity for J. sigillata. AMOVA analysis revealed that significant genetic variation was mainly distributed within population as 73% in J. regia and 76% in J. sigillata. The genetic differentiation (FST) was 0.307 between the two walnut species (p < 0.0001), which was higher than FST values within populations (J. regia FST = 0.265 and J. sigillata FST = 0.236). However, the STRUCTURE analysis of the J. regia and J. sigillata populations revealed two genetic clusters in which gene introgression exists, therefore, the boundary of separation between these two walnut species is not clear. Moreover, these results were validated by NJ and UPGMA analysis with additional conformation from the PCoA. Based on the SSR data, our results indicate that J. sigillata is an ecotype of J. regia. Taken together, these results reveal novel information on population genetics and provide specific geographical regions containing high genetic diversity of the Juglans species sampled, which will assist in future conservation management.

The effect of cropping system on the distribution of organic carbon (OC) and nitrogen (N) in soil aggregates has not been well addressed, which is important for understanding the sequestration of OC and N in agricultural soils. We analyzed the distribution of OC and N associated with soil aggregates in three unfertilized cropping systems in a 27-year field experiment: continuously cropped alfalfa, continuously cropped wheat and a legume-grain rotation. The objectives were to understand the effect of cropping system on the distribution of OC and N in aggregates and to examine the relationships between the changes in OC and N stocks in total soils and in aggregates. The cropping systems increased the stocks of OC and N in total soils (0–40 cm) at mean rates of 15.6 g OC m-2 yr-1 and 1.2 g N m-2 yr-1 relative to a fallow control. The continuous cropping of alfalfa produced the largest increases at the 0–20 cm depth. The OC and N stocks in total soils were significantly correlated with the changes in the >0.053 mm aggregates. 27-year of cropping increased OC stocks in the >0.053 mm size class of aggregates and N stocks in the >0.25 mm size class but decreased OC stocks in the <0.053 mm size class and N stocks in the <0.25 mm size class. The increases in OC and N stocks in these aggregates accounted for 99.5 and 98.7% of the total increases, respectively, in the continuous alfalfa system. The increases in the OC and N stocks associated with the >0.25 mm aggregate size class accounted for more than 97% of the total increases in the continuous wheat and the legume-grain rotation systems. These results suggested that long-term cropping has the potential to sequester OC and N in soils and that the increases in soil OC and N stocks were mainly due to increases associated with aggregates >0.053 mm.

Heavy metals contaminate the soil that alters the properties of soil and negatively affect plants growth. Using microorganism and plant can remove these pollutants from soil. The present investigation was designed to evaluate the induced effect of Bacillus pumilus on maize plant in Cadmium (Cd) contaminated soil. Three different concentrations of Cd (i.e. 0.25, 0.50 and 0.75 mg kg−1) were applied in soil under which maize plants were grown. The germination percentage, shoot length, leaf length, number of leaves, root length, fresh weight and nutrient uptake by maize plant were determined. The experiment was conducted by using complete randomized design (CRD) with three replicates. The result indicated that germination percentage, Shoot length, leaf length, root length, number of leaves, and plant fresh weight were reduced by 37, 39, 39, 32 and 59% respectively at 0.75 mg kg−1 of CdSO4 concentration but when maize seeds inoculated with Bacillus pumilus significantly increased the germination percentage, shoot length, leaf length, number of leaves, plant fresh weight at different concentrations of CdSO4. Moreover, the plant protein were significantly increased by 60% in T6 (0.25 mg kg−1 of CdSO4 + inoculated seed) and Peroxidase dismutase (POD) was also significantly higher by 346% in T6 (0.25 mg kg−1 of CdSO4 + inoculated seed), however, the Superoxide dismutase (SOD) was significantly higher in T5 (0.75 mg kg−1 of CdSO4 + uninoculated seed) and was 769% higher as compared to control. The Cd contents in Bacillus pumilus inoculated maize roots and shoots were decreased. The present investigations indicated that the inoculation of maize plant with Bacillus pumilus can help maize plants to withstand Cd stress but higher concentration of Cd can harm the plant. The Bacillus pumilus has good potential to remediate Cd from soil, and also have potential to reduce the phyto availability and toxicity of Cd.

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Cyclic nucleotide gated ion channels (CNGCs) in plants have very important role in signaling and development. The study reports role of CNGC19 and CNGC20 in salt stress in A. thaliana. In-silico, genome wide analysis showed that CNGC19 and CNGC20 are related to salt stress with maximum expression after 6 h in A. thaliana . The position of inserted T-DNA was determined ( in-vivo) through TAIL-PCR for activation tagged mutants of CNGC19 and CNGC20 under salt stress. The expression of AtCNGC19 and AtCNGC20 after cloning under 35S promoter of expression vectors pBCH1 and pEarleyGate100 was determined in A. thaliana by real-time PCR analysis. Genome wide analysis showed that AtCNGC11 had lowest and AtCNGC20 highest molecular weight as well as number of amino acid residues. In-vivo expression of AtCNGC19 and AtCNGC20 was enhanced through T-DNA insertion and 35S promoter in over-expressed plants under high salt concentration. AtCNGC19 was activated twice in control and about five times under 150 mM NaCl stress level, and expression value was also higher than AtCNGC20 . Phenotypically, over-expressed plants and calli were healthier while knock-out plants and calli showed retarded growth under salinity stress. The study provides new insight for the role of AtCNGC19 and AtCNGC20 under salt stress regulation in A. thaliana and will be helpful for improvement of crop plants for salt stress to combat food shortage and security.

Purpose: Heavy metals contaminate the soil that alters the properties of soil and negatively affect plants growth. Using microorganism and plant can remove these pollutants from soil. The present investigation was designed to evaluate the induced effect of Bacillus pumilus on maize plant in Cadmium (Cd) contaminated soil. Methods: Three different concentrations of Cd (i.e. 0.25, 0.50 and 0.75 mg kg-1) were applied in soil under which maize plants were grown. The germination percentage, shoot length, leaf length, number of leaves, root length,fresh weight and nutrient uptake by maize plant were determined. The experiment was conducted by using complete randomized design (CRD) with three replicates. Results: The result indicated that germination percentage, Shoot length, leaf length, root length, number of leaves, and plant fresh weight were reduced by 37, 39, 39, 32 and 59% respectively at 0.75mg kg-1 of CdSO4concentration but when maize seeds inoculated with Bacillus pumilus significantly increased the germination percentage, shoot length, leaf length, number of leaves, plant fresh weight at different concentrations of CdSO4. Moreover, the plant protein were significantly increased by 60% in T6 (0.25 mg kg-1 of CdSO4+inoculated seed) and Peroxidase dismutase (POD) was also significantly higher by 346% in T6 (0.25 mg kg-1 of CdSO4+inoculated seed), however, the Superoxide dismutase (SOD) was significantly higher in T5 (0.75 mg kg-1 of CdSO4+ uninoculated seed) and was 769% higher as compared to control. The Cd contents in Bacillus pumilus inoculated maize roots and shoots were decreased. Conclusion: The present investigations indicated that the inoculation of maize plant with Bacillus pumilus can help maize plants to withstand Cd stress but higher concentration of Cd can harm the plant. The Bacillus pumilus has good potential to remediate Cd from soil, and also have potential to reduce the phytoavailibility and toxicity of Cd.