Verification of Glyphosate Resistance, Lepidopteran Resistance and Wide Compatibility of Male Sterile Line E1C4008S in Rice

Abstract

Weeds and insect pests are two important biotic stresses resulting in yield loss in rice, and wide compatibility is the essential characteristic of breeding inter-subspecific hybrid rice. This study focused on glyphosate resistance, lepidopteran resistance and wide compatibility as well as identification of molecular and some agronomic characteristics of transgenic male sterile line E1C4008S. The results indicated that glyphosate resistance gene Epsps# and lepidopteran resistance gene Cry1ca# were transferred into japonica wide compatibility male sterile line 4008S by Agrobacterium-mediated method, and four independent transformation events named E1C4008S-1, E1C4008S-2, E1C4008S-3 and E1C4008S-4 were obtained, in which E1C4008S-3 and E1C4008S-4 were of single copy insertion. The EPSPS protein contents of E1C4008S-3 and E1C4008S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 300.58 to 1410.69 μg/g at the tillering stage. The glyphosate tolerable concentration (dosage) of E1C4008S-3 and E1C4008S-4 reached at least 16 g/L (54.42 kg/hm2), and the seeds of E1C4008S-4 can germinate normally on the medium containing 1 g/L glyphosate. The CRY1C protein contents of E1C4008S-3 and E1C4008S-4 in different organs were significantly different both in descending order of leaf > stem > root, and ranged from 0.62 to 2.43 μg/g at the tillering stage. The larvae mortalities of rice leaf rollers fed on leaves of E1C4008S-3 and E1C4008S-4 for 5 d were 95.35% and 97.77%, respectively, while the average mortalities of silkworms fed with protein extracts from leaves of E1C4008S-3 and E1C4008S-4 reached 94.55% and 83.64%, respectively. The results suggested that wide compatibility and evaluated agronomic traits of E1C4008S-4 were not significantly changed by insertion of the exogenous genes. Overall, a novel male sterile germplasm with glyphosate resistance, lepidopteran resistance and wide compatibility was verified to be developed in rice. Keywords: rice, glyphosate resistance, lepidopteran resistance, wide compatibility, male sterile line, bioengineered crop