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Physostegia virginiana Benth. (false dragon head flower), belonging to the family Lamiaceae, is a perennial plant and is usually used as landscape plant in parks and wetlands in China. It is also widely used as an ornamental plant for cut-flower all over the world (Cardin et al. 2007). In June 2019, leaf spot symptoms were observed on P. virginiana in Zibo botanical garden of Shandong Province, China (36.79°N, 118.02°E). We surveyed about 200 square meters of planting area, and most of the infected plants were close to the water or wet places, with ~20% disease incidence which were concentrated in the lower leaves of plants. The symptoms appeared on leaves were mostly round or oval spots, light to dark brown in color, and 3 to 8 mm in diameter. Severe leaf lesions were linked together, causing early fall of leaves. Small pieces of 15 infected leaves were collected to confirm the causal pathogen. The samples were sterilized by 70% ethanol for 30 s, 5% NaClO for 1 min, then rinsed in sterile water three times, plated on potato dextrose agar (PDA) and incubated at 25℃ in the dark for 7 days (Zhu et al. 2013), and 7 isolates were obtained from 10 diseased samples. The stroma of fungal mycelium was initially white, gradually turning dark green to black, while the margin of colony was regular, with concentric rings which were black sporodochia aggregates. Conidiophore hyaline, produce 2-3 order complex branches, arising as 3-4 conidiogenous cells from the tip of the branches, conidiogenous cells ampulliform to cylindrical. Conidia were aseptate, unicellular, hyaline, cylindrical, and their dimensions varied from 4.8 to 8.2 × 1.7 to 2.4 μm with rounded tips. The morphological characteristics of the isolates matched features described for Paramyrothecium roridum (Tode) L. Lombard & Crous, comb. nov. (Lombard et al. 2016). For molecular identification, genomic DNA was extracted from five representative single spore isolates. The partial coding genes of internal transcribed spacer (ITS) and calmodulin (cmdA) from the original isolates were amplified with primers ITS1/ITS4 and CALDF1/CALDR1 (White et al. 1990; Lawrence et al. 2013), respectively. The sequenced genes (GenBank accession no. MT318535, and MT454826) exhibited 98.71%, and 100.00% homology with type specimen of P. roridum strain CBS372.50 (GenBank accession no. MH856665.1, and KU846271.1), respectively, confirming the morphological identification. Pathogenicity of the fungus was tested indoor by inoculating 5 living, healthy P. virginiana plants with 3 leaves, which were inoculated with 10 µl of conidial suspension (2 × 105 conidia/ml) from a 10-day-old cultures on PDA, while 5 other inoculated plants with 10 µl of sterile water were served as controls. Treated plants with the inoculated leaves were covered by plastic bags in the greenhouse of 14 h light/10 h dark with ~80% relative humidity at 25℃. As time went by (about 3-7 days), the leaves inoculated with conidial suspension appeared similar symptoms as described above, whereas negative controls were still healthy. The same pathogens were isolated from the diseased leaves and repeated three times with same results as those that were obtained previously from the outdoor plants, including morphological and molecular results which confirm Koch's postulates. To our knowledge, this is the first record of P. roridum causing leaf spot on P. virginiana in China. The finding is beneficial to the better application of P. virginiana, a very common ornamental plant.

A total of 407,663 expressed sequence tags (ESTs) of wheat, barley, maize, rice, and sorghum, obtained from GenBank/dbEST, were used to search for simple sequence repeats (SSRs). A total of 10,253 EST-SSRs, which accounted for 2.52% of all the ESTs, were identified. Using Primer Premier 5.0, 1367 EST-SSR primer pairs were designed, of which 715 with high quality were synthesized. The 715 primer pairs were tested on wheat, rice, maize, cotton, and soybean under the same PCR conditions, and the effective primer pairs in the five crops were 500 (69.93%), 383 (53.57%), 452 (63.22%), 357 (49.93%), and 388 (56.27%), respectively. This indicated a high transferability of EST-SSR markers between far-ranging species. In addition, 139 EST-SSR primer pairs with 240 loci were localized on all the 21 wheat chromosomes by using Chinese Spring nulli-tetrasomic lines of wheat.

A new genetic linkage map was constructed based on recombinant inbred lines (RILs) derived from the cross between the Chinese winter wheat (Triticum aestivum L.) varieties, Chuang 35050 and Shannong 483 (ChSh). The map included 381 loci on all the wheat chromosomes, which were composed of 167 SSR, 94 EST-SSR, 76 ISSR, 26 SRAP, 15 TRAP, and 3 Glu loci. This map covered 3636.7 cM with 1327.7 cM (36.5%), 1485.5 cM (40.9%), and 823.5 cM (22.6%) for A, B, and D genome, respectively, and contained 13 linkage gaps. Using the RILs and the map, we detected 46 putative QTLs on 12 chromosomes for grain yield (GY) per m2, thousand-kernel weight (TKW), spike number (SN) per m2, kernel number per spike (KNS), sterile spikelet number per spike (SSS), fertile spikelet number per spike (FSS), and total spikelet number per spike (TSS) in four environments. Each QTL explained 4.42–70.25% phenotypic variation. Four QTL cluster regions were detected on chromosomes 1D, 2A, 6B, and 7D. The most important QTL cluster was located on chromosome 7D near the markers of Xwmc31, Xgdm67, and Xgwm428, in which 8 QTLs for TKW, SN, SSS and FSS were observed with very high contributions (27.53–67.63%).