Study On Genetic Characterization Of The Interspecific Hybird Progenies Between Luffa Acutangula (L.) Roxb And Cylindrical (L.) Roem

Luffa acutangula(L.) Roxb(2n=26) and Luffa cylindrical(L.) Roem(2n=26) possesses many complementary valuable traits.Luffa cylindrical(L.) Roem possesses high yield, disease resistance for Luffa acutangula(L.) Roxb,including disease resistance to virue and increase of production.Meanwhile,Luffa acutangula(L.) Roxb has good edible qualities and the flesh without browning after cooking for Luffa cylindrical(L.) Roem,including improvement of qualifies,without browning after cooking and so on.In the present study,the different categories of Luffa were used as core material for further investigation based on former research progresses.The hybrid progenies(F₁,F₂,B₁,B₂) have been gotten via the interspecific cross.Studies on genetic characteristics of the hybrid progenies(F₁,F₂,B₁,B₂) from the interspecific cross with morphology,further cytogentic and molecular analyses. The detailed results as following:1 Segregations of plant height,leaf number,leaf width,leaf length,node length,first stalk length,first note of male flower,first note of female flower,female flowers number,rate of fruit development,fruit length and pollen viability in F₂ progenies derived from interspecific cross Luffa acutangula(L.) Roxb×cylindrical(L.) Roem were observed.The results showed that the interspecific F₂ progenies segregated transgressively,forming much variation.F₂ pollen viability is lower than F₁.F₂ has lower worthiness in breeding utilization.2 Through analysis of genetic characterization on four agronomic traits of the hybrid progenies from the interspecific cross Luffa acutangula(L.) Roxb×cylindrical(L.) Roem, bitterness,flowering time,arris,flower color four traits were studied.The results showed that the bittemess in hybrid progenies may be a quality character determined by the two genes which were independent genetic relatively.The relation between the genes was dominant supplement each other(DSEO).Flowering time,arris,flower color follow heredity of quantitative characters.3 Cytological studies were conducted on pollen mother cells(PMCs) meiosis of hybrid progenies from the interspecific cross Luffa acutangula(L.)Roxb×cylindrical(L.) Roem.Resuit showed that two parents have normal meiosis of PMCs.However,hybrid F₁,F₂ have abnormal meiosis of PMCs,there were particularities in metaphaseâ… ,some of the chromosomes were found not to rank at metaphase plate in metaphaseâ… .In anaphaseâ… ,there were lagged chromosomes.At tetrad stage,dyad,dyad with mocronucleus,triad,tetrad with mocronucleus and polyad appeared.Abnormal meiosis of PMCs was the cytogenetic reason for fertility reduction of hybrid progenies.4 Orthogonal design was used to optimize ISSR amplification system on Luffa In four factors(Taq DNA polymerase,Mg²⁺,dNTPs,primers)at three levels respectively.A suitable ISSR reaction system was established,namely 20μL reaction system containing 10×PCRbuffer, 2.5mmol/LMg²⁺,250μmol/LdNTPs,0.25μmol/Lprimer,1UTaq DNA polymerase,and 30 ng DNA template.The optimal annealing temperature for ISSR-PCR reaction was proposed by gradient PCR.5 This study was carried out in order to uncover the laws of genetic segregation in the interspecific progenies from Luffa acutangula(L.)Roxb×cylindrical(L.) Roem.The DNAs isolated from the parents,F₁ hybrid,F₂ and B₁ progenies were amplified for ISSR analysis using 9 primers.Forty-eight bands were amplified,among which 19 bands were common to both parents,20 and 9 bands were Luffa acutangula(L.)Roxb and Luffa Cylindrical(L.)Roem -specific,respectively.Statistical analysis of the band pattems showed that F₂ progenies inherited more genetic components from Luffa cylindrical(L.)Roem than from Luffa acutangula(L.) Roxb.The genetic component from Luffa cylindrical(L.) Roem was eliminated in B₁ progeny faster than in F₂ progeny.