Genetic Model Analysis And SSR Marker On Ear Tip-barren Trait In Maize

Maize (Zea Mays L.) is one of the most important cereals in the world. The supply ofMaize production can not meet the demands with the ultilization of feedstuff, starch, energy andmedicine industry. Therefore we concentrate on yield potentiality extremely excavated and highyield-variety cultivated. During the process of yield potentiality excavated,the most importantlosses factor is the phenomen of aborted kernels and florets without fecundation at the tip of ear.A large number of barren tip materials with good resistance are abandoned, good quality, wideadaptability, a large part of whose quality potentiality is excellent, however these excellentInbred lines are not applied to production practices, it is not only result in the waste of resources,but also becomes a difficult problem in breeding. Researches of predecessors are mostly inphysical development, nutrition supply, environment affect outside and so on, while it is tooweak in genetic algorithms and molecular basis, which lead to improvement and utilization ofvariety limited.The paper anlayzed the genetic models of ear tip-barren between666(tip-barrenless)×T6093(tip-barren) by six joint analysis of P1、P2、F1、F2、B1and B2.(Amongwhich barren tip of T6093ear is outside the husk, namely female ear of maize husk cannotpackage the entire ear, for which top of female ear is exposure, furthermore the exposed partsare all barren tip, this is different from the research of predecessors in barren tip inside the husk.)And combined with SSR Molecular Markers technology, use the method of combination ofgenotype and phenotype, to calculate the recombination rate, and calculate the matching rate atthe same time, mark the sites that affect barren tip of maize ear character, further elaborate thegenetic mechanism of barren tip ears.The result showed are:1.The ear tip-barren and the tip-barrenless are a quality trait controlled by2pairs ofdominant genes. The ear tip-barren type was postive and the tip-barrenless type are negative.2.The bare tip length increased with the spike length and row number per ear but dcreasedwith the ear diameter.It has positive correlation with spike weight and100-seed weight.3.The genetic models of length of ear tip-barrenness were fitted by twoadditive-dominance-epistasis major gene plus additive-dominance polygenes mode（E-1），Themajor gene heritability of3ancestry generation(B1，B2，F2)was64.41%、64%and77.07%and the polygene heritability was25.24%,0%and12.31%. The major gene heritability are greaterthan the polygene heritability of ear tip-barren trait in the3ancestry generation.The eartip-barren Trait of maiz is mainly influenced by major gene control, is less influenced by theenvironmental factors.4. According to the results of SSR markers, the two genes which controlled the maize eartip-barren trait were preliminary located on the chromosome2.01and7.06.