Variation in alleles contributes to the ability of a population to adapt to a variable environment. Yet, this variation is often controlled in cultivated crops for ease of productionfor example, with sorghum, all seeds germinate at roughly the same time, plants grow to a uniform height, and seeds ripen at the same time. In contrast, shattercane has seeds with variable states of dormancy, plants that grow taller than sorghum, and seeds that disperse via a shattering mechanism, ensuring dispersal before the sorghum crop is harvested. By crossing shattercane with cultivated sorghum, the authors compared how the crop-wild hybrid performed relative to its crop and wild parents in a number of traits that may be important to its ecological fitness.
By experimentally manipulating temperature conditions, the authors found different germination patterns for the three types of seeds. Although the crop-wild hybrid responded to low temperatures similarly to its wild shattercane parentboth in terms of percentage of seeds that germinated and by staying dormant and delaying germinationit responded to high temperatures similarly to its cultivated sorghum parent; non-germinated seeds of both sorghum and the hybrid died. This may be linked to their seed structures. Shattercane seeds are completely enclosed by glumes, whereas those of sorghum are only partially covered,
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American Journal of Botany