Background Oryza glumaepatula represents an important resource of genetic diversity that can be used to improve rice production. However, hybrid sterility severely restricts gene flow between Oryza species, and hinders the utilization of distant heterosis in hybrid rice breeding. Results In order to fully exploit the beneficial genes of O. glumaepatula and facilitate the conservation of these gene resources, a set of chromosome single-segment substitution lines (SSSLs) was developed using an indica variety HJX74 as the recurrent parent and an accession of O. glumaepatula as the donor parent. During the process of SSSLs development, S23 , a locus conferring hybrid male sterility between O. sativa and O. glumaepatula , was identified and fine mapped to 11.54 kb and 7.08 kb genomic region in O. sativa and O. glumaepatula , respectively, encoding three and two candidate ORFs, respectively. qRT-PCR and sequence analysis excluded one common ORF as the candidate gene. In addition, hybrid male sterility caused by S23 was environment-sensitive, and could be observed only in natural short-day (NSD). Conclusion Identification and candidate genes analysis of S23 in this study provides a valuable example to study the crosstalk between interspecific F 1 hybrid male sterility and environment-conditioned male sterility in rice, facilitates reserving and utilizing favorable genes or alleles of wild Oryza species, and allows for a more efficient exploitation of distant heterosis in hybrid rice breeding. Electronic supplementary material The online version of this article (10.1186/s12284-019-0271-4) contains supplementary material, which is available to authorized users.

No abstract

No abstract

Chemical and enzymatic modifications intended to improve the reactivity of dissolving pulp rapidly decrease its yield. In this study, a beating posttreatment intended to increase the reactivity of bamboo dissolving pulp was investigated. Beating post-treatment can create microfibrils on the surface of fibers. The reactivity of unrefined bamboo dissolving pulp prepared via pre-hydrolysis and a subsequent kraft cooking and Op-H-P (oxygen delignification enhanced with H 2 O 2 and sodium hypochlorite) bleaching process was very low. The reactivity increased drastically as the Canadian standard freeness (CSF) of the bamboo dissolving pulp was decreased (i.e., the degree of beating increased). The CSF decreased to 236 mL from its original, higher freeness. The average fiber width was larger and the curling and kink indexes were lower in the pulp of CSF 236 mL compared to those of pulps with greater freeness. However, there was little impact of beating on the crystallinity index of bamboo dissolving pulp.

No abstract

In the present study, carboxymethyl cellulose nanofibrils (CMCNFs) with different carboxyl content (0.99–2.01 mmol/g) were prepared via controlling the ratio of monochloroacetic acid (MCA) and sodium hydroxide to Eucalyptus bleached pulp (EBP). CMCFs-PEI aerogels were obtained using the crosslinking reaction of polyethyleneimine (PEI) and CMCNFs with the aid of glutaraldehyde (GA). The effects of pH, contact time, temperature, and initial Cu2+ concentration on the Cu2+ removal performance of CMCNFs-PEI aerogels was highlighted. Experimental data showed that the maximum adsorption capacity of CMCNF30-PEI for Cu2+ was 380.03 ± 23 mg/g, and the adsorption results were consistent with Langmuir isotherm (R2 > 0.99). The theoretical maximum adsorption capacity was 616.48 mg/g. After being treated with 0.05 M EDTA solution, the aerogel retained an 85% removal performance after three adsorption–desorption cycles. X-ray photoelectron spectroscopy (XPS) results demonstrated that complexation was the main Cu2+ adsorption mechanism. The excellent Cu2+ adsorption capacity of CMCNFs-PEI aerogels provided another avenue for the utilization of cellulose nanofibrils in the wastewater treatment field.

No abstract

A high reactivity is an essential prerequisite for dissolving pulp. In this study, xylanase modification to increase the reactivity of bamboo dissolving pulp was investigated. The original reactivity of a bamboo dissolving pulp prepared by a prehydrolysis kraft pulping process and bleached by (OP)-H-P (oxygen delignification enhanced with peroxidesodium hypochlorite -peroxide) is very low. The reactivity of the pulp was increased drastically after xylanase modification, which lowered the pulp's pentosan content. Simultaneously, the crystallinity index of the dissolving pulp decreased slightly after xylanase modification. The microscopic appearance of the fiber surfaces changed slightly. The average curl and kink indices were lower at a xylanase charge of 1.0 IU/g compared to the other charges, while changes to the yield loss and the degree of polymerization were negligible. The mechanism for the increased pulp reactivity is discussed.