Institute of Evolution, University of Haifa, Mt. Carmel, 31905, Haifa, Israel.
Theor Appl Genet. 1992 Sep;84(7-8):958-62. doi: 10.1007/BF00227410.
We compared and contrasted calorimetrically heat production in seedlings incubated at 5°C and 24°C using genotypes from cold and warm Israeli populations of the wild progenitors of barley (Hordeum spontaneum) and wheat (Triticum dicoccoides). The wild barley sample comprised 14 accessions, 7 from cold localities and 7 from warm localities. The wild emmer wheat sample consisted of 12 accessions, 6 from a cold locality, and 6 from a warm locality. Our results indicated that (1) heat production was significantly higher in the two wild cereals at 5 °C than at 24 °C; (2) interspecifically, wild barley generates significantly more heat than wild wheat at both 5 °C and 24 °C; (3) intraspecifically, wild barley from warm environments generates significantly more heat than wild barley from cold ones, at 24 °C. We hypothesize that both the inter- and intraspecific differences in heat production evolved adaptively by natural selection in accordance with the niche-width genetic variation hypothesis. These differences presumably enhance biochemical processes, hence growth, thereby leading to the shorter annual cycle of barley compared to that of wheat, and may explain the wider range of the wild and cultivated gene pools of barley, as compared with those of wheat. We propose that a shortening of the growth period through utilizing heat production gene(s) is feasible by classical methods of breeding and/or modern biotechnology.
我们比较和对比了在 5°C 和 24°C 下培养的幼苗的量热产热，使用的基因型来自野生大麦（Hordeum spontaneum）和小麦（Triticum dicoccoides）的以色列冷、暖种群。野生大麦样本包括 14 个品系，7 个来自寒冷地区，7 个来自温暖地区。野生二粒小麦样本由 12 个品系组成，6 个来自寒冷地区，6 个来自温暖地区。我们的结果表明：（1）在 5°C 时，两种野生谷物的产热量明显高于 24°C；（2）种间而言，在 5°C 和 24°C 时，野生大麦的产热量明显高于野生小麦；（3）种内而言，在 24°C 时，来自温暖环境的野生大麦的产热量明显高于来自寒冷环境的野生大麦。我们假设，产热量的种间和种内差异是通过与生态位宽度遗传变异假说一致的自然选择而适应性进化的。这些差异可能增强了生化过程，从而促进了生长，导致大麦的年周期比小麦更短，并且可能解释了与小麦相比，大麦的野生和栽培基因库的范围更广。我们提出，通过经典的育种方法和/或现代生物技术利用产热基因来缩短生长周期是可行的。
