Plastid Inheritance, Physiology, and Fitness in Medicago sativia

最近的研究表明，双亲遗传的质体(BIP)在植物界可能比之前认为的更常见。在所研究的被子植物中，大约20%的叶绿体是双亲遗传的。人们提出了各种假说来解释植物中叶绿体遗传模式的基础，然而，关于这些遗传模式的进化意义却知之甚少。我们对紫花苜蓿(Medicago Sativa)的研究表明，在该物种中，可能存在与孢子体组成(母本、父本或双亲)相关的适应效应。在具有BIP的物种中，质体也可能为发育中的微配子体、精子或受精卵提供能量来源。这里描述的研究将考虑对BIP存在的这两种可能的解释。利用一组具有特定组成的全同胞家系，我们建议测量1)孢子体组成对紫花苜蓿基本生理过程和适合度组成的影响。测量将集中在受叶绿体-核相互作用影响的生理特性和可能反映初级代谢差异的全植物特性上。

Recent research demonstrates that biparental inheritance of plastids (BIP) may be more common in the plant kingdom than previously thought. Plastids are inherited biparentally in approximately 20% of angiosperm taxa studied. Various hypotheses have been presented to explain the basis for patterns of plastid inheritance in plants, however, very little is understood regarding the evolutionary significance of these inheritance patterns. Our research with alfalfa (Medicago sativa), which exhibits regular BIP, suggests that there may be fitness effects associated with sporophyte plastid composition (maternal, paternal, or biparental) in this species. Plastids may also provide an energy source for the developing microgametophyte, sperm or the fertilized egg in species with BIP. The research described here would consider these two possible explanations for the existence of the BIP. Using sets of full-sib families with defined constitutions, we propose to measure the effects of 1) plastid composition in sporophytes on basic physiological processes and components of fitness in alfalfa. Measurement would concentrate on physiological traits influenced by plastid-nucleus interaction and whole-plant characteristics that may reflect differences in primary metabolism.