| There are potential mutual interference between male and female functions of bisexual plants as male parent and female parent.In order to reduce the mutual interference between male and female functions,the hermaphroditic plants usually alleviate this conflict by different ways of adaptation,such as dichogamy and herkogamy,and then promote cross-pollination.Heterostyly is the hetero morpic herkogamy phenomenon in this background,showed in two or three morphs in the same population.There are three typical characteristics of reciprocal herkogamy,heterotypic incompatibility system,ancillary polymorphisms of stigma and pollen morphology.In the previous investigation of Limonium chrysocomum population,it was found that the combination of the morphs had some characteristics of the heterostyly,but it was different from the typical distyly or tristyly.It is a matter of concern that what polymorphism of heterostyly or heterotypic incompatibility system that Limonium chrysocomum had.For this reason,we made a survey about the population structure,floral characters,ancillary polymorphisms of stigma and pollen morphology,pollen dispersal,pollinator type and heterotypic incompatibility system in Limonium chrysocomum which distribute in XingJiang,results are as follow: 1)Limonium chrysocomum which distributed in different populations are all composed of long-styled morph(L-morph),short-styled morph(S-morph),homo-styled morph(H-morph),the morph with lightly higher pistils than stamens(PL-morph)and the morph with lightly higher stamens than pistils(PS-morph).SHZ and BL population were similar,which mainly with S-morph and H-morph,L-morph was less,the number of transitional morph PS is 5-6 times of PL;YW population is mainly H-morph,L-morph and S-morph were less,the number of transitional morph PS and PL were similar.2)Three populations had different flowering time,the SHZ population entered the flowering period in the middle and early days of May;the YW population was a little late in the flowering time,which entered the flowering period in the middle and late days of May;the population which is distributed in Sayram Lake entered the flowering period in the middle of June,flowering period is about 20 days.There was no significant difference in single flower opening dynamics among different morphs of the same population.Single flower life is about two days.3)The floral traits parameters of five style-morphs in SHZ and YW populations were observed.There were no significant differences in whole flower length,corolla diameter,calyx length,pollen number,ovules number and abortion rate of different style-morphs.The pollen surface ornamentation and stigma shape are dimorphism.The stigma of L-morph is corn grain shape,pollen ornamentation is polygonal coarse gridding;the stigma of L-morph is papillate,pollen ornamentation is polygonal fine gridding;stigma surface morphology and pollen ornamentation of H-morph were similar with L-morph and S-morph.4)The types of pollinators of the Limonium chrysocomum were mainly Bombus Spp.,Pierisrapae Linne,Polyomommatus eros,Apismel lifera and so on.The visitation rates of long-tongued and short-tongued pollinators showed no visiting preference among morphs,the frequency of visiting flowers was 0.017±0.0059 times/flower/h and 0.06±0.019 times/flower/h,respectively.In several major pollinators,bumblebees have the highest frequency of visiting flowers,followed by butterflies and bees,the frequency of visiting flowers was 0.057±0.018 times/flower /h,0.017±0.0059 times/ flower/h,0.0038±0.0011 times/flower/h,respectively,none of the insect types showed variation in visitation rates in response to different floral morphs(F=4.674,P=0.072>0.05).5)Artificial pollination experiments showed that: the seed setting rate between the same morph(L*L、S*S)of pollination was 0,the seed setting rate between the different morphs(L*S、S*L)of pollination was 35.29±11.95% and 39.02±7.71%,respectively.Natural seed setting rate between L-morph and S-morph was 38.17±5.62% and 27.12±4.11%,respectively;there was no difference of seed setting rate between the L-morph and H-morph.All three morphs showed strong heterotypic incompatibility.6)L-morph and S-morph with interactive correspondence had different interactivity index and morph deviation index in different populations.Interactivity index of L-morph and S-morph in SHZ population was 0.04867 and 0.03916,respectively;morph deviation index was 0.67.Interactivity index(0.00398,0.0326)and morph deviation index(0.18)of L-morph and S-morph in YW population were lower than SHZ population.7)The ability of three morphs to adhere different pollen types was detected in YW populations.Intermorph pollen number(65.18±10.83)much higher than intarmorph pollen number(34.3±4)in S-morph,there was no difference in pollen counts of two types between L-morph and H-morph.The difference of the papilla morphology of the stigma may be one of the reasons for the different adhesion of pollen.8)The three populations had the same morph constitutions,but different morph frequencies.The deviation of floral ratio may be the cause of different seed setting rate among morphs.Although the length of the pistils and stamens of different morphs were obvious,stigma and pollen had dimorphism and heterotypic incompatibility.In the absence of interactivity correspondence,the identificated function between the stigma and pollen grains promotes the transmission of pollen. |
