| Plant cytoplsmic male sterility (CMS) is a common phenomenon in higher plants and is manifested as the inability of a produce viable pollen. CMS is a trait of economic importance in the production of hybrid seed from crop plants as it eliminates the need for emasculation. A correlation between CMS and unique arrangements of the mitochondrial (chloroplast) genome has been found. CMS systems make excellent models for studying nuclear-cytoplasmic interactions because fertility restoration relies upon nuclear-encoded gene products that suppress cytoplasmic dysfunction. In the study reported here. Ultra-structural observation on the microsporgenesis, analysis of physiological and biochemical bases, CAPS and RFLP analysis for mitochondrial DNA and chloroplast DNA, as well as in Jin A CMS line. The main results are summarized as blow.1. we had found that the auxocyte abortion of Jin A took place at the stage of sporogenous cell division-microspore mother cells formed. Through ultra-structure observation, it is found that the microspore of Jin A began to abort at the stage of sporogenous cell division. During the abortion period of the CMS line, the ceil membrane of microspore and tapetum dissolved, cytoplasm degenerated, the cell organelles such as mitochondria and plastid and the tapetal cells became degenerated and disorganized. In addition , it is found that nuclear and cytoplasm began to concentrated in tapetal cells, these are morphological features of PCD. So, we think that tapetal cells disorganization may be one type of PCD that occurs in plants. Certainly, these must be proved on molecular level.2. A correlation between CMS and varies of activity of enzymes. The activity of four enzymes with mitochondrial function in cotyledon, leaf and anther of Jin A cytoplasmic male sterile and in those of its maintainer line. The results showed that activity of peroxide (POD), cytochrome oxidase (COD), superoxide dismutase (SOD) and succinic dehydrogenase in the anther of the sterile line were lower than those in the fertile line; but such differences were not found between the leaves of the sterile line and the fertile line, and only the activity of succinic dehydrogenase was lower in the cotyledon of the sterile line than that of fertile line.3. CMS is maternally inherited trait. Both the chloroplast and the mitochondrial genomes can be maternally inherited in higher plants; however, to date, only mitochondrial genome mutations have been correlated with cytoplasmic male sterility (CMS). A correlation between CMS and unique rearrangements of the mitochondrial genome has been found. Cleaved Amplified Polymorphic Sequence (CAPS) wassuccessfully applied to analyze the organelle composition among Jin A its maintainer 104-7A and sterile with cytoplasm of Gossypium harknessii. Five chloroplast and three mitochondrial universal primer pairs were used. All mitochondrial primer pairs (nad I exon B-nad 1 exon C,18SrRNA-5SrRNA, nod exon 1-nad 4 exon 2) and four chloroplast primer pairs ( rbcL-rbcL, rbcL-PSA I, TrnH-TrnK, TrnD-TrlT) of the five ehloroplast primer pairs, were efficiently amplified, but no polymorphism was detected, when the PCR products were digested by eighteen restriction endonucleases, including, Alu I , Bshl236 I. BsuR I, Csp6 I, Hin6 I, HpaII. Rsa I, Taq I Trul1 . Msp I, EcoR.I. EcoRV. Pst I, HindIII BamH I . Beg I . Beg II Xba I and Sal I respectively, eight polymorphic cpDNA-CAPS markers (rbcL-PSA I / Bshl236 I, rbcL-PSA I / BsuR I, rbcL-PSA I / Hin6 I, rbcL-PSA I / Rsa I, TrnH-TrnK/ Bshl236 I, TrnH-TrnK/ Csp6 I, TrnH-TrnK/ Rsa I, TrnH-TrnK/ Taq I ) were found and no mtDNA-CAPS marker was found. In this research, four lines of cotton were used for mitochondrial RFLP, including JinA,104-7A,the cytoplasm of G. harknessii Brandegee three types of cytoplasms. The plentiful polymorphism has been detected in some probe/enzyme combinations (atp9/HindIII,cox II/BamH, cox II /EcoR I, coxII/EcoR V). The RFLP results can be used for classification of CMS lines quickly and also gives...
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