Maize (Zea mays L.) stalk rot, caused primarily by the soilborne fungal pathogen Fusarium spp., reduces maize quality and yield worldwide. This study was undertaken to develop and utilize a rapid continuous injection inoculation technique to evaluate maize inbred lines for resistance to Fusarium spp. under field conditions, which could facilitate the identification and development of new sources of host resistance to manage the disease. Continuous injection inoculation is a rapid, stable, and simple method that can evaluate the resistance of maize inbred lines to Fusarium stalk rot (FSR) within 20 days. To verify the feasibility and reliability of the inoculation method, Fusarium graminearum, F. proliferatum, and F. subglutinans were isolated, identified, and inoculated into maize at the six-leaf stage (V6) by a veterinary adjustable bottle continuous vaccination syringe. Our results showed that, of a total of 97 inbred maize lines, 6 (6.2%) showed high resistance to maize stalk rot, 20 showed resistance (20.6%), 32 were susceptible (33.0%), and 39 were very susceptible (40.2%). Based on simple sequence repeat markers, an analysis of molecular variance indicated a significant correlation between population of the inbred maize line and resistance to FSR (P = 0.001). Overall, this study provided a systematic, rapid, stable, and simple identification method for maize inbred lines resistant to FSR in the field. At the same time, this method was also suitable for genetic diversity analysis of maize inbred lines resistant to FSR.

Alfalfa root rot caused by Fusarium tricinctum is one of the most important soilborne diseases, resulting in significant losses to alfalfa agriculture worldwide. Fungicides used in management of the disease affect the environment and human health. In this study, a strain of Ochrobactrum intermedium (I-5), isolated from alfalfa rhizosphere soil, exhibited strong antifungal activity against a number of causative pathogens of alfalfa root rot and showed the strongest antagonistic activity against F. tricinctum (a longest radius/shortest radius ratio of 3.09). When applied at 10%, a filtrate of the strain liquid culture significantly reduced the spore production and germination and mycelial growth of F. tricinctum, and the inhibition rates were 76.67, 78.93, and 55.77%, respectively. Furthermore, a filtrate and suspension of the strain, when applied at 10%, reduced alfalfa root rot by >73% in repeated experiments. The strain clearly promoted the activities of invertase, urease, cellulose, and neutral phosphatase in alfalfa rhizosphere soil and significantly reduced the damage to rhizosphere soil quality attributable to alfalfa root rot. Moreover, the strain clearly promoted the growth of alfalfa without causing any evident damage to plants. The active substance produced by the strain was insensitive to heat and ultraviolet irradiation and displayed optimal efficacy at pH 8. To the best of our knowledge, this is the first study describing the use of O. intermedium for the biological control of alfalfa root rot. O. intermedium (I-5) has potential for application in the control of alfalfa root rot and improvement of the quality of cultivated alfalfa.

Begonia semperflorens Link. et Otto is widely grown in China for ornamental purposes as well as its edible blossom. In July of 2017 and 2018, a leaf spot of B. semperflorens was observed in many fl...

Cockscomb (Celosia cristata L.), is grown in the garden as an ornamental plant and also used in traditional medicine for the treatment of headache, sores, skin eruption, painful menstruation and ca...