The Research on Identification of Resistance to Sorghum Aphid [Melanaphis Sacchari(Zehntner)] Employing Indoor Artificial Infestation Technique

[ Objective] The paper was to establish a quick and effective indoor identification method of sorghum resistance to aphid uninfluenced by seasons. [ Method] Based on the indoor reproduction technique of aphids, the sorghum varieties with different resistant performances against aphids in fields were conducted inoculation test in the laboratory according to different seedling culture media, different survey periods of aphid quantity, different leaf ages for inoculation, different inoculation quantity of aphids and different aphid sizes. Three hundred sorghum materials were identified in both laboratory and field. [ Result ] The number of aphids per seedling on the fifth day after inoculation gave the best score of plant resistance to sorghum aphid by using the loam as the seedling culture media, and inoculating three different sizes of aphids in seedlings at two-leaf stage. Thus, the indoor identification technique of resistance to sorghum aphids was as follows ： （ 1 ） sorghum seeds were sown in loam at room temperature of 22 - 26 ℃ and air humidity of 55% - 75% ; （2） three aphids with different sizes were inoculated in scedIings at two-leaf stage; （3） the number of aphids per seeding were surveyed on the fifth day after inoculation; （4） plant resistance to sorghum aphid was evalu- ated according to number of aphids per seedling on the fifth day after inoculation. The resistant grade of sorghum variety was evaluated according to distribution of aphid quantity per seedling in a 100-seedlings population. The resistance materials identified by indoor method at seedling stage had consistent performance with fidd identification. [ Conclusion] The method could be used for resistance identification of sorghum varieties and hybrids, and accurate identification and selectlon of individual resistance of hybrid offspring, which could improve selection efficiency of individual resistant plant against aphids in hybrid offspring and identification accuracy of individual resistant plant among molecular marker population.

Development of Triticum aestivume——Leymus mollis Translocation Lines and Identification of Resistance to Stripe Rust

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widely distributed and destructive fungal diseases worldwide. Since 1995, most Chinese wheat cultivars have lost their stripe rust resistance due to the subsequent emergence of the new races CYR30, CYR31, CYR32, and CYR33 （Han et al., 2010）. Therefore, it is necessary to seek effective resistance genes and develop new resistance germ- plasm for wheat resistance breeding.

Identification and Cloning of Resistance Gene Analogues (RGAs) Encoding NBS-LRR Proteins from Gossypium arboreum L.

Plants have developed a complicated defense mechanism during evolution to resist the harmful pathogens they encountered.The mechanism involves the interaction of the plant resistance(R)