The Characteristics And Transfer Research Of The Zea Mays L.Cross-Incompatibility Ga1(Gametophyte Factors1) Gene

Maize gametophyte Gal (Gametophyte factors1) gene with unilateral cross-incompatibility characteristic, has broad application prospects in maintaining special maize purity, isolating GMO maize, utilizing maize heterosis and so on. In this study, we use different gametophyte genotype maize inbred line and their hybrids as experimental materials. We research the hybrid seed rates, pollen tube growth behavior and pollen competition, in order to reveal the characteristics and the relationships between Gals, Gal-m and gal alleles of Gal loci, then apply them to maize. The results of the study are as follows:1, The analysis of maize inbred line Mo17(galgal),48-2(galgal),401D (Gal-sGal-s),401J (Gal-mGal-m) and their F1hybrids show that:401D as female parent, the average hybrid seed rates of Mo17and48-2respectively are2.4%and1.2%. Our results, suggest that dominant homozygous Ga1-sGal-s gene is unilateral cross-incompatibility to recessive homozygous galgal gene.401J as female parent, the average hybrid seed rates of Mo17and48-2respectively are78.1%and87.0%. These observations suggest that dominant homozygous Gal-mGal-m gene have not the unilateral cross-incompatibility characteristics to recessive homozygous galgal gene. Besides, the reciprocal cross between401D and401J separately are85.0%and76.7%, indicating Gal-sGal-s and Gal-mGal-m have not cross-incompatibility. JD (401Jx401D) as female parent, the average hybrid seed rates of Mo17and48-2respectively are42.4%and57.4%. the results Show that Gal-mGal-s gene is a certain degree of unilateral cross-incompatibility to recessive homozygous galgal gene.2, The analysis of pollen tube behavior observation, Mo17pollen tube can only grow2.2cm in the401D silk, indicating Gal-sGal-s exhibit strict cross-incompatibility against gal pollen. MD (Mo17×401D) self-cross pollen tube growth rate is0.89cm.h-1,but Mo17×MD is0.45cm.h-1, indicating Gal-sgal own weak cross-incompatibility against gal pollen. On the Contrary, Mo17pollen with401J and MJ (Mo17×401J) filaments grown normally, indicating Gal-m silk do not exist cross-incompatibility against the gal pollen. JD (401Jx401D) self-cross pollen tube growth rate is0.52cm.h-1,but the growth rate of Mo17pollen on JD filaments is0.31cm.h’1, indicating Gal-mGal-s silk show moderate cross-incompatibility against gal pollen.401D,401J, MD, MJ, JD and Mo17pollen on Mo17silk grown normally,Indicating gal silk have not cross-incompatibility with Gal-s, Gal-m and gal pollen.3, In order to verify the pollen competitive relationship of Gals, Gal-m and gal, using pollen purple marking0362and a recessive sul sweet maize as materials, we analyze hybrid incompatibility between401D,401J, Mo17,48-2, and their hybrids of F1for identification and evaluation.401D as female, mixing equal amounts of0362and401D pollen, Ear color Yellow:Purple=99:1, indicating that the dominant Gal-sGal-s gene prefers to Gals pollen, almost no gal pollen. At the same time, the MD and4D as the female parent, mixing equal amounts of0362and401D pollen, the results respectively are Yellow:Purple=90.6:9.4and Yellow:Purple=97.1:2.9, Similarly indicating dominant heterozygous Gal-sgal gene favors Gals pollen,but a small amount of gal pollen. The analysis of self-cross and reciprocal cross about F1(D) and F1(J),recessive sul sweet maize with401D and401J hybrids,we obtain the following results.F1(D) self-cross, non-sweet:sweet=6.9:1, F1(D)xFl(J), non-sweet:sweet=7.1:1, indicating that Gals silk accepte equally Gals and Gal-m pollen; F1(J) self-cross, non-sweet:sweet=3.3:1, F1(J)×F1(D), non-sweet:sweet=3.3:1, indicating that the gene containing Gal-m silk equal access Gals, Gal-m and gal pollen.4, The research of Gal (Gametophyte factors1) gametophyte gene transfer to waxy maize. Waxy maize (wxl) as the female parent,401D male parent, hybrids get Fl. Subsequently, Fl hybrids as male parent, wxl as recurrent parent backcross, obtain45BC1generations. Electe5backcross families carrying Galsgal gene by mixing pollination BC1populations, than get BC2. The number of five families are21,16,17,21,49. Select separately one carrying Gal-sgal gene from5families, and then backcross, finally get BC3. So far, it has planted five BC3families, if we continue backcross,we will get BC4families. Select Galsgal plants by by mixing pollination, then self-cross,obtain BC4S1families which carrying GalsGals. Finally get BC4S2, in which no purple grain ear is cross-incompatibility gene waxy maize, carrying GalsGalswxlwxl.