环境对动物体型和暴露附器大小的影响已有大量研究,但对两性异形的影响研究尚不多见,本文研究了旱地沙蜥Phrynocephalus helioscopus3个地理种群形态的两性异形和地理变异,综合了Bergmann法则、Allen法则和Rensch法则分析其体型、四肢和尾部大小的变化规律.结果表明,伊宁和塔城种群的雌、雄亚成体体型差异无统计学意义(P＞0.05),北屯市雄性体型显著大于雌性(P＜0.05);伊宁和北屯种群的雌性成体体型均显著大于雄性(P＜0.05),但塔城地区两性体型差异无统计学意义(P＞0.05).协方差分析结果表明,亚成体两性间只有塔城地区的雄性前肢长显著大于雌性(P＜0.05);3个地区雄性成体均具有较大的后肢和尾部(P＜0.01),伊宁市雌性具有较长的前肢(P＜0.05),塔城和北屯市两性前肢长差异均无统计学意义(P＞0.05),3个地区旱地沙蜥的体型呈反Bergmann法则的现象;四肢和尾部的大小遵循Allen法则;体型、前肢长、后肢长和尾长不遵循Rensch法则.旱地沙蜥3个地理种群受弥散性的自然选择压力比定向性的繁殖力选择和性选择的作用更强.%Environmental impact of animal body size and exposed parts has been extensively studied,but its influence on sexual dimorphism is still elusive.We studied sexual dimorphism and geographical variation of morphology in 3 populations of toad-headed agama lizard (Phrynocephalus helioscopus),and combined analyses of Bergmann's rule,Allen's rule and Rensch's rule were conducted on the variation of body,limbs and tail size.The results of t-test showed that juveniles were sexually dimorphic in body size (snout-vent length,SVL) of Beitun city (P ＜ 0.05) with males having longer SVL except Yining city or Tacheng prefecture (P ＞ 0.05).Adults from Yining city and Beitun city were sexually dimorphic (P ＜ 0.05) with females having longer SVL except Tacheng prefecture (P ＞ 0.05).Analysis of covariance (ANCOVA) showed that juveniles from Beitun and Yining city did not show a sexual dimorphism in fore limb length (FLL),hind limb length (HLL) and tail length (TL) (P ＞ 0.05),while male juveniles having longer FLL from Tacheng prefecture but not in HLL or TL.Among adults,males had larger HLL and TL (P ＜ O.01) from 3 populations,but females had larger FLL from Yining city (P ＜ 0.05) except Beitun city and Tacheng prefecture.Body size exhibited an anti-Bergmann's rule,while the size of the limbs and tail followed Allen's rule.Body size,fore limb length,hind limb length and tail length did not follow Rensch's rule from the three populations.Pressure from diffused natural selection played a stronger role than that of fecundity advantage selection and sexual selection in 3 populations of P.helioscopus.
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