Identification And Analysis Of Genes Related To Heading Date In A Wheat RIL Population

The Sichuan Basin is one of the main wheat producing areas in China.The wheat planting system in the region is changing from the"three-crop system of wheat and jade"to the"two-crop system of rice and wheat".In the"rice and wheat double cropping"rotation system,the early-seeding and early-maturing type is an ideal type of wheat variety.It can make full use of the light and heat resources after rice harvest,and can also solve the problem of wheat yield reduced problems due to high-temperature ripening in the late flowering period.In addition,the heading period of wheat is highly correlated with the maturity period,and is mainly affected by the genes of vernalization and photoperiod,In order to clarify the genetic mechanism of the growth and development characteristics of early-seeded and early-maturing wheat varieties,and to mine the corresponding linkage markers,which is hoped to guide breeding practice,variety improvement and molecular marker-assisted breeding,this study used parents 02 Jian 2/Pin 6933,Fan 37123,and their continuous selfing"one-grain transmission"method to obtain a total of 234 materials of F₅generation RIL population as materials,using vernalization and photoperiod gene primers which had been developed to identify and analysis the vernalization and photoperiod genes of the materials,the main results obtained are as follows:1.The effective accumulated temperature at the heading-flowering stage is significantly negatively correlated with the flowering period and plant height,and the correlation coefficients are-0.799 and-0.242,respectively,and have a significant positive correlation with the thousand-grain weight,the correlation coefficients is 0.392.The number of grains has no significant correlation,and there is no significant correlation with the number of effective spikes and spike grains.2.Independent sample T test showed that the light-blunt gene Ppd-D1a can advance the jointing stage,heading stage,and flowering stage,and increase the thousand-grain weight without significant effect on the effective ear and ear grain number;The light-sensitive gene Ppd-D1b can delay the jointing stage,heading stage,and flowering stage,and will reduce the 1000-grain weight without affecting the effective ears and the number of ears.3.The light-blunt gene Ppd-D1a can advance the heading period of wheat,thereby increasing the time from heading to flowering and the effective accumulated temperature,without affecting the effective ears and the number of spikes per ear,the 1000-grain weight is increased,which is beneficial to the increase in wheat yield;The light-sensitive gene Ppd-D1b has a postponement effect on the heading period,which can reduce the time from heading to flowering and the effective accumulated temperature,without affecting the effective ears and the number of spikes per ear,the 1000-grain weight decreased,which reduced the wheat yield.4.The allelic variation site of the photoperiod gene Ppd-D1,the light-blunt gene Ppd-D1a and the light-sensitive gene Ppd-D1b are closely linked to the heading stage of the trait,located at 33,951,651bp-33,961,438bp on Chr2D,and the size is 9787bp,This positioning result is the same as that of the predecessors.5.When wheat is a spring or weak spring material,low temperature vernalization is not a necessary condition for wheat heading,and its heading period is mainly affected by the photoperiod genes Ppd-D1a and Ppd-D1b.6.The use of photoperiod gene markers Ppd-D1F/Ppd-D1R2 to breed weak spring wheat varieties containing the light-blunt gene Ppd-D1a is more suitable for the special ecological climate conditions and planting patterns in the Sichuan Basin,which is conducive to the improvement of wheat yield.