Selection Of Breeding Base And Research Of Cold-irrigation Technology For Two-line Hybrid Sterile Line

Multiplying techniques by irrigating cold water in reservoir for TGMS line is the one of the main methods to breed and produce the two-line sterility line,which has the characteristics of controllability,overcoming environmental obstacles and high & stable yield,etc.Based on the production practice of TGMS line for State Plan “863” located in DongAn town,Gao Zhou city,this paper discuss the TGMS line including Xin'an S,Guangzhan 63-4S,1892 S,Tannong S and Guangzhan 63 S on the base selection and multiplying techniques with cold water from seed sowing,transplanting to harvest.Results are as follows:1.We should select breeding base for PTGMS(photo-thermo sensitive genic sterile male line)including Guangzhan series and 1892 S series in Baoding city,Yunnan province as main base and Sanya,Hainan province as subsidiary in case there is big climate change in Baoding during breeding period which may lead to the breeding failure.TGMS line with low fertility transfer temperature like Tannong S should select breeding base with cold water irrigation conditions.2.Temperature sensitivity of different TGMS line varies a lot.Under the sunlight and temperature condition of first half year in Maoming,the duration from seeding to heading shortens with the delay of sowing time and remains no difference with early sowing time.For the sterile line with long growth duration,the sowing time is usually carried on Jan 10 th – Jan 15 th and for the sterile line with short growth duration,sowing time should be arranged on Jan 25 th – Jan 30 th.While for the TGMS line with low fertility transfer temperature like variety Tannong S,it's better to sow the seed on Jan 10 th which could take advantage of the low temperature in April to reach the natural sterility transfer effect.3.Due to the different genetic background of sterile lines,the initial temperature for fertility alteration and the reaction to cold temperature varies from each other along with the different growth duration,which lead to the quite different requirement for the total cold water irrigation days for suitable high-yielding multiplication.The specific numbers are respectively 12 days for 1892 S,13-14 days for Guangzhan 63 S,15-16 days for Xin'an S and Guangzhan 63-4S,and above 23 days for Tannong S.4.The fertility and cold resistance of sterile line is the main basis to control the water temperature during cold water irrigation,which should not be too low to guarantee the balanced sterility transfer of the plants in field.For the nuclear sterile line with high fertility as 1892 S,Guangzhan 63-4S and Xin'an S,we should apply light or less irrigation.For the sterile line with better resistance and low fertility transfer temperature,we should apply deep irrigation with initial depth above 25 cm and 30 cm more in later stage.5.The temperature of cold irrigation varies according to different nuclear sterile line.For 1892 S,Guangzhan 63-4S and Xin'an S with high fertility,the scope of temperature is wide between 20 ?-23.5?,while for Tannong S with low fertility transfer temperature,the scope is narrow between 21?-22? and 23? as highest.Application depth should keep in deep irrigation from beginning to the end of cold irrigation which may have better fertility transfer6.The cold-irrigation multiplication in Spring of Maoming is proceeded under the condition of low temperature and sufficient water source.According to different tolerance to the low temperature in early period,cold irrigation in middle & later period and pest & disease,we should change the seedling raising method by applying less irrigation,improving resistance and building rational high yielding structure.