Creating a novel herbicide-tolerance OsALS allele using CRISPR/Cas9-mediated gene editing

Weeds and weedy rice plague commercial rice fields in many countries. Developingherbicide-tolerance rice is the most efficient strategy to control weed proliferation. CRISPR/Cas9-mediated gene editing, which generates small InDels and nucleotide substitutions atand around target sites using error-prone non-homologous end joining DNA repairing, hasbeen widely adopted for generation of novel crop germplasm with a wide range of geneticvariation in important agronomic traits. We created a novel herbicide-tolerance allele inrice by targeting the acetolactate synthase (OsALS) gene using CRISPR/Cas9-mediated geneediting. The novel allele (G628W) arose from a G-to-T transversion at position 1882 of OsALSand conferred a high level of herbicide tolerance. Transgene-free progeny carryinghomozygous G628W allele were identified and showed agronomic performance similar tothat of wild-type plants, suggesting that the G628W allele is a valuable resource fordeveloping elite rice varieties with strong herbicide tolerance. To promote use of the G628Wallele and to accelerate introgression and/or pyramiding of the G628W allele with other elitealleles, we developed a DNA marker for the G628W allele that accurately and robustlydistinguished homozygous from heterozygous segregants. Our result further demonstratesthe feasibility of CRISPR/Cas9-mediated gene editing in creating novel genetic variation forcrop breeding.

Non-escaping frost tolerant QTL linked genetic loci at reproductive stage in six wheat DH populations

Reproductive stage frost poses a major constraint for wheat production in countries such as Australia.However,little progress has been made in identifying key genes to overcome the constraint.In the present study,a severe frost event hit two large-scale field trials consisting of six doubled haploid(DH)wheat populations at reproductive stage(young microspore stage)in Western Australia,leading to the identification of 30 robust frost QTL on 17 chromosomes.The major 18 QTL with the phenotype variation over 9.5%were located on 13 chromosomes including 2 A,2 B,2 D,3 A,4 A,4 B,4 D,5 A,5 D,6 D,7 A,7 B and7 D.Most frost QTL were closely linked to the QTL of anthesis,maturity,Zadok stages as well as linked to anthesis related genes.Out of those,six QTL were repetitively detected on the homologous regions on 2 B,4 B,4 D,5 A,5 D,7 A in more than two populations.Results showed that the frost damage is associated with alleles of Vrn-A1 a,Vrn-D1 a,Rht-B1 b,Rht-D1 b,and the high copy number of Ppd-B1.However,anthesis QTL and anthesis related genes of Vrn-B1 a and Ta FT3-1 B on chromosomes 5 B and 1 B did not lead to frost damage,indicating that these early-flowering phenotype related genes are compatible with frost tolerance and thus can be utilised in breeding.Our results also indicate that wild-type alleles Rht-B1 a and Rht-D1 a can be used when breeding for frost-tolerant varieties without delaying flowering time.

The Average Errors for Linear Combinations of Bernstein Operators on the Wiener Space

In this paper, we discuss the average errors of function approximation by linear combinations of Bernstein operators. The strongly asymptotic orders for the average errors of the combinations of Bernstein operators sequence are determined on the Wiener space.

On the Average Errors of Multivariate Lagrange Interpolation

In this paper, we discuss the average errors of multivariate Lagrange interpolation based on the Chebyshev nodes of the first kind. The average errors of the interpolation sequence are determined on the multivariate Wiener space.

Average widths and optimal recovery of multivariate Besov classes in L_p(R^d)

Some weak asymptotic results for average σ-K width and average σ_L width of the isotropic Besov classes S r pθB(R d), S r pθb(R d) and the anisotropic Besov classes S r pθB(R d), S r pθb(R d) in L p(R d) (1≤p<∞) are obtained, and the corresponding weak asymptotic optimal subspaces are identified. Furthermore, the weak asymptotic behavior of optimal recovery is established for the isotropic Besov classes S r pθB(R d) in L p(R d) (1≤p≤∞).

Average B-width and infinite-dimensional G-width of some smooth function classes on the line

The exact values of average σ_B width and infinite dimensional σ_G width of Sobolev class B\+r\-p(R) in the metric L\-p(R)(1≤p≤∞) are obtained and the exact (σ∈N) and strong asymptotic (σ>1) results of infinite_dimensional σ_G width of Sobolev_Wiener class W\+r pq(R) in the metric L\-q(R) and its dual case_W\+r\-q(R) in the metric L qp(R)(1≤q≤p≤∞) are achieved.