樟科(Lauraceae)部分属种雌蕊群维管分布格局及其系统学意义

Vascular patterns and systematic significance of gynoecia in some genera and species of Lauraceae

运用石蜡切片技术 ,对樟科的紫楠〔Phoebesheareri (Hemsl.)Gamble〕、浙江楠 (Ph .chekiangensisC .B .Shang)、香樟〔Cinnamomumcamphora (Linn .)Presl.〕、浙江桂 (C .chekiangensisNakai)、细叶香桂 (C .subaveniumMiq .)、江浙山胡椒 (LinderachieniiCheng)、钓樟 (L .reflexaHemsl.)、狭叶山胡椒 (L .angustifoliaCheng)、乌药〔L .aggregata (Sims)Kosterm .〕、红脉钓樟 (L .rubronerviaGamble)和山苍子〔Litseacubeba (Lour.)Pers .〕等 4属11种植物雌蕊群的维管分布格局进行了连续解剖观察 ,结果表明 ,成熟雌蕊群仅有 1枚心皮 ,具 1背缝维管束、1腹缝维管束 (部分保留 2束 ) ,并有可能是由具多数离生心皮 (或多或少不同程度趋向联合 ) ,且各心皮具数枚胚珠的祖先类群经历心皮数目、胚珠数目的逐步减少所形成的假单基数合生心皮 (假单心皮 )。这一结果及推论不仅与Cronquist等关于樟科雌蕊群的观点相吻合 ,而且对樟科雌蕊群的系统发育作了进一步阐述。观察还发现樟科植物心皮结构的原始性 ,即心皮远轴端未真正愈合。

Through the gynoecium successive sections, vascular patterns were investigated for 11 Lauraceous species in four genera, e.g. \%Phoebe sheareri \%(Hemsl.) Gamble, \%Ph. chekiangensis \%C. B. Shang, \%Cinnamomum camphora \%(Linn.) Presl., \%C. chekiangensis \%Nakai, \%C. subavenium \%Miq., \%Lindera chienii \%Cheng, \%L. reflexa \%Hemsl., \%L. angustifolia \%Cheng, \%L. aggregata \%(Sims) Kosterm., \%L. rubronervia \%Gamble, \%Litsea cubeba \%(Lour.) Pers. The results suggested that the gynoecium with pattern of 1 dorsal vascular bundle and 1 ventral vascular bundle (sometimes bifurcated) has the monomerous character (but pseudomonomerous), which indicate that the gynoecium of modern Lauraceae is possibly evolved from polycarpellary gynoecia of the ancestor. This conclusion supports A. Cronquist′s opinion concerning the Lauraceae gynoecia. Further phylogenetic deduction was also presented for this group. In addition, the Lauraceous carpels, which may not substantively fuse abaxially, were demonstrated to be primitive.