Karyotype Variation in Leea L
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KARYOTYPE VARIATION IN LEEA L. S.P. KARKAMKAR AND V.P. PATIL Department of Genetics <fe PlanI Breeding, MACS Reserch Institute, Law College Road, Pune -411 004. (Accept September 1992) Karyomorphologicai studies of 15 Leea species revealed the chromosome number as 2n=24 except for tour teinploid species, viz., L. crispa, L. gigantea, L. herbacea and L. robuita wlierein the number was 2n=48. Chromosomes were either median or submedian, though ihere were variations in chromosome lengths. Total length of the haploidcompiemenl was minimum in L. ratuijMand maximum in L, eequata among diploid species. Among tetraploid species, it was relatively lowest inL. robusia and highest in L. herbacea. Based on median and submedian chromosomes, and total chromosome length of haploid complement, it is suggested thatspecies with relatively highrrcomplemcnt length appeared to be of recent origin. There was only one pair of SAT-chromosomes in the complement except fort./i4fr(Kicea, which had two SAT-pairs. All these variations have been discussed in detail. Key words: Karyotypes, chromosomc morphology, SAT-chromosomes. The genus Leea L. belongs to the grape family L. latifolia Konkan Vitaccaecomprising about 130species distributed in L. macrophylla Karnataka tropics and subtropics. Screening of the available L. rubra Middle Andanun species for resistance to major fyngal pathogens L. robusia Khandala suggested these to be immune (Patil et a!., 1990). It L. sambucina Varandha Ghat is, therefore, a prereQuisite to collect the information L. setuligera Khandala on cytology of these wild relatives to trace the Detailed analysis has been done by following the relationships with grapes as also to exploit the possi toot tip squash method (Shamia and Mookeijea, bility of their use in the improvement of grapes. 1955). Ten well separated metaphase plates were Cytological studies in this family is restricted selected and sketched with camcra lucida under oil to chromosome numbers only (Fedorov, 1969), though immeision objective at bench level. Numerical .se few reports arc available on karyotype analysis Quence of individual chromosomes in the complement (Vatsala, 1960; Sudarshan Raj and Seclhaiah, 1969, was given according to the criteria adapted by Scars 1973; Hazra and Sharraa, 1970; Patil and Jadhav, (1958) and Riley (1963), starting with longest and 1980). Hence, an attempt has been made to study in ending with the shortest. The chromosomes were deta i I the ka ryomorphology of 15 species of this genus assigned to different types based on their relative Leea. length, position of ccntromcrc and SAT-chrortosome. MATERIALS AND METHODS The abbreviations used for the purpose arc M=niedian, Sm=submedian, sl=SAT chromosome. Leea species studied alongwith localities are given Chromosome types include also the following: below ; A=1.00 to 2.00//m, B=2.00 to 3.00//m, C=3.00 to Name of species Locality 4.00 ^m . Leea acuminata Khasi hills L. aequata Khandala RESULTS Long Island, Andaman L. angulata Data recorded on total chromosome length, anii L. aspera Khandala . ratio (longe.st/sbortcst chromosomc), coefficient of L. crispa Konkan variability in the somatic complements of the above L. gigantea Middle Andaman 15 species arc presented in Tabic 1. L. herbacea KJbasi bills L. indica Western Ghat Out of fifteen types studied, eleven types have L. javanica South Andaman chromosome number 2n=24 and four types have chro- species. Number of chromosomes with median constrictions are maximum inL. indica, L. crispa and L.robusta whereas minimum number is noted in A. acuminata, L. aequata, L. aspera and L. herbacea. Number of chromosomes with submedian constric tions are more in L. acuminata, L. aequaia, L. aspera, L. latifolia and L. herbacea and less inZ.. indica, L. crispa and L. rubra (See plate I and II). Coefficient of variability forchromosonie lengths in the complement is found to be more or less similar with total chromosome length and ratio of longest to shortest chromosome in the species studied. Out of 15 species studied, only one species L. herbacea has two pairs of SAT-chromosonies and in rest of the species there is only one pair of SAT- chromosomes. SeQuence number of SAT-chromo- somes varies from I to V. In majority of species, longest chromosome pair was the SAT-pair. All the species have submedian SAT-chromosomes except for L. acuminata in which the SAT-chromosonies appeared to be sub-terminal (see plate II). ''r A DISCUSSION Chromosomc number Chromosome numbers < t ' V studied in 15 species of Leea revealed 11 species having 2n=24 and in remaining four species the •< 'f< number is 2n=48. The present findings confirm earlier 8 reports on chromosome number as 2n=24, e.g., in L. sambucina (Shetty and Raman, 1960; Mehra, 1976; Pali! el a!., 1980 and Nagare, 1982). However, in the same species. Gill et al. (1979) have reported n=24. Varialioas in this number as n=10 by Nair and Nam- Figures 1-9, 1, Camera Lucida Drawing (C.L.D.) of somatic meia- bisaii(l957),2n=22by Vatsala (1960) and 2n=24,26 phasc plate of h. acuminala x 24Q0/<m, 2. Phoiomicrograph (Ph.M.) and 52 by Hazra and Shamia (1970) have been noted. of somatic meiaphase plaic of L. acguaia x 2460 /an. 3. C.LD . of somalic racUphase plate of i,. aspera x 2330^m. 4. C.LD. of somatic Similarly, variations in chromosome numbers as meophase plate of L. indxca x 2476 //m. 5. C.L.D. of somaiic n=IO, II, 12 in L. iW/co (Khosla, 1978) have been meiaphase plau*. of L- macrophylla x 24C)0/-<m. 6. Ph.M. of soaiaiic reported earlier, Ridsdale (1974) observed n=28 raetaphase plate of L. ruhra x 2470 ^/m. 7. Ph.M. of somalic meia- phasi- plaie o f l . samhucl/ia .x 2025/^ra. 8. Ph.M. of somalic mctii- in I, crispa. Nagare (1982) reported n=24 phasc plate ofL. hertxicea x I660^m . 9. C.LD . of somatic meiaphase for the same species, whereas, Mehra and Khosla plate of A. rohusto x 2660 ^m. (1969) and Mehra (1976) observed n= 12. Chromosome morphology Data on karyomor- nior.onie number 2n=48. Total length of Ihe haploid phology of 15 Leea species suggest the chromo complements was maximum in L. herbacea (54.79 somes to have median or subn>edian constriclions. /im) and minimum in L. acuminata (24.65 /<m). Spe Such karyotypes, with more or less similar cies have been arranged in ascending order for total chromosome size and median or submedian centro haploid length of the complement (Table 1). This mere have been termed as symmetrical karyotypes order al.so appears to be more or less parallel with by Stebbins (1950). Mean numberof chromosomes longest/shortest chromosomc ratio for individual with median centromeres is relatively more in L. Carybotype variation \nLeea L. able 1 ■ Ch/oiDosome morphology in L 'ca species. ,pecics 2n= Longesl Shortest ToiaJ chro- Longesiy Coeffi- Karyotype formula (n) chrom o chrom o' mosomf shoncsi cienf of som e (L) some (S) length of chrom oso variabi fim haploid mes (IvS) lity set {um) ,)iplold species I, acuminata 24 2.92 1.38 24.65 2,116 0,1982 lSmslB+3SmA+4SmB+2MA+2MB I. indica 24 3.12 1.58 26.43 1,977 0,2053 lSmslC+3SmB+4MA+4M13 I aspera 24 2.83 1.60 26.90 1,770 0,1701 lSmslB+'2SmA + 5SmB+2MA + 2MB J. nngulala 24 2.94 1.58 27,02 1,861 0,1970 lSmslR+2SmA + 3SmBt2MA+4MB 1 suruligem 24 2.83 1.57 27.55 1,800 0,1835 lSmslB+5SmB*4MA*2MB 1. nthra 24 3.29 1.76 28.13 1,870 0,1875 lSmstC+ lStnA+4SmB+2MA<-4MB /.. samhuctna 24 3.61 1.61 29,31 2,020 0.2417 lSmslC+4SniB+2SmC+3MA<-2MB 1 iiivanica 24 3.22 1.75 30.20 1,840 0.1775 lSmslC+lSmA+3SniB + 2SmC + lMA-t 4M13 /,. macrophylla 24 3.30 1.60 30.28 2,060 0.2159 ISmslC f lSinA+4SmB + lSmr<2MA<- 2MB^ 1 MC /.. lalifoha 24 3.61 1.66 31.27 2,175 0.2337 lSmsK>4SmB+2Sm('+2MA + 3MB I acquata 24 3.78 1.48 34.49 2.550 0.2138 lSmslB + 3SmAf4SmBt2MAt2MB 1 ftraplold sp ed es / robm^ta 48 2.73 1.33 45.89 2.050 0.1839 lSmsiB + 2SmA+3SmB + 13MA + 5MB I. cnspa 48 2.78 1.49 48.48 1,870 0,1744 lSmslB+lSmA+,5SmBtl3MA<-4MB ! ^igantca 48 3.39 1.J3 51,23 2,220 0,2054 ISmslC ^2SmAf6SniB+9MA<-6MB I herhacea 48 3.48 1.50 54,79 2.320 0,2252 2Sm,';tr+2SmA<-8SmB<-2SniC'+6MA + 4MR iiiliiiniiiii lllliliiiiiiii ' llllllllllllillll IIIIllllllllllltllllllHlllllllllillllliiiiii ioiUii iiiiHiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii I I !l h«rc«c«« iiii II mil n il k* m«cropHYl1» Plale II Idiograms of L eai species. indica, L. crispa And L. robusia. Total length of the Nagare M B \982Cyto-taxonomic studies in Vitaceat haploid complement of these species is highest in L. M Sc Thesis University of Poona. herbacea (54.79 fim) and lowest in L. acuminata Nair N C & P N N Nambisan 1957 Contribution to (24.65 //m). the floral morphology and embryology ofZ,. sambuc- Coefficient of variability showed more or less ina W M Bot Not n o 160-172. parallel trends with the lengths of longest and shortest Patil S G, B K Honrao, V G Rao & V P Patil 199(1 chromosomes. Screening of grape (VilLs species) germplasm for It is normally expected to get one pair of SAT- resistance to three major fungal diseases, Indian chromosomes in diploid and two pairs in tetraploid Journal of Agricultural Sciences 60 836-38.