Data from: Effects of habitat fragmentation on parental correlations in the seed rain of a bird-dispersed species

Seed dispersal plays a crucial role in natural forest regeneration.
Changes in the seed rain due to anthropogenic habitat alteration can
influence seedling recruitment patterns and affect the evolutionary
dynamics of populations. Using a combined endocarp-embryo microsatellite
assay of naturally dispersed seeds, we concomitantly quantify the
contribution of contemporary pollen and seed dispersal to the genetic
structure of the seed rain of the shrub species Pistacia lentiscus L. The
study was conducted in two consecutive seasons at four forest fragments
embedded in contrasting (connected vs. isolated) landscapes. Interseasonal
variation in the parental genetic structure of the seed rain was assessed
through analysis of molecular variance, and paternal and maternal
correlations and effective parental numbers were computed for different
fragments and microhabitats (within fragments) using genetic kinship
analysis. Temporal variation in the genetic structure of the dispersed
seeds was higher for maternal gametes, reflecting a more temporally
variable contribution of individual mother plants to the seed rain, as a
potential consequence of masting and/or natural heterogeneity. Higher
effective numbers of fathers than mothers were consistently observed in
all studied forest fragments and microhabitats, the difference being more
pronounced for connected than for isolated fragments. The effective number
of mothers, directly influenced by disperser birds’ behavior, was
apparently insensitive to fragmentation. Despite potentially high mobility
of pollen by wind and seeds by birds, habitat fragmentation could
influence the parental structure of dispersed seeds, with potential
consequences for the genetic structure of the adult generation.

种子扩散（seed dispersal）在天然林更新中发挥着至关重要的作用。由人为生境改变引发的种子雨（seed rain）变化，能够影响幼苗招募模式，并改变种群的进化动态。本研究针对自然扩散的种子，采用内果皮-胚联合微卫星（microsatellite）检测技术，同步量化了当代花粉扩散与种子扩散对灌木物种乳香黄连木（Pistacia lentiscus L.）种子雨遗传结构的贡献量。本研究于两个连续季节，在嵌入于两类迥异（连通型与隔离型）景观的4个森林片段中开展。通过分子方差分析，本研究评估了种子雨亲本遗传结构的季间变异；并借助遗传亲缘关系分析，针对不同森林片段及片段内微生境，计算了父本、母本相关性与有效亲本数量。扩散种子遗传结构的时间变异在雌配子中更为显著，这反映出单株母本对种子雨的贡献在时间上波动更大，这可能是大年结实或自然异质性所导致的结果。在所有研究的森林片段与微生境中，均观测到父本有效数量显著高于母本有效数量，且该差异在连通型片段中比隔离型片段更为突出。受传播鸟类行为直接影响的母本有效数量，显然不受生境破碎化的影响。尽管花粉可借助风力、种子可依靠鸟类实现较高的移动性，但生境破碎化仍能够影响扩散种子的亲本结构，进而可能对成年植株世代的遗传结构产生影响。