A Y Kiros, E Mica, R Battaglia, E Mazzucotelli, M Dell'Acqua, L Cattivelli, F Desiderio
Center of Plant Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
Council for Agricultural Research and Economics (CREA) - Research Centre for Genomics and Bioinformatics, Fiorenzuola d'Arda, Italy.
Front Plant Sci. 2024 Aug 26;15:1390401. doi: 10.3389/fpls.2024.1390401. eCollection 2024.
Wheat grain yield is a complex trait resulting from a trade-off among many distinct components. During wheat evolution, domestication events and then modern breeding have strongly increased the yield potential of wheat plants, by enhancing spike fertility. To address the genetic bases of spike fertility in terms of spikelet number per spike and floret number per spikelet, a population of 110 recombinant inbred lines (RILS) obtained crossing a ssp. cultivar (Latino) and a accession (MG5323) was exploited. Being a modern durum and a semi-domesticated genotype, respectively, the two parents differ for spike architecture and fertility, and thus the corresponding RIL population is the ideal genetic material to dissect genetic bases of yield components. The RIL population was phenotyped in four environments. Using a high-density SNP genetic map and taking advantage of several genome sequencing available for , a total of 94 QTLs were identified for the eight traits considered; these QTLs were further reduced to 17 groups, based on their genetic and physical co-location. QTLs controlling floret number per spikelet and spikelet number per spike mapped in non-overlapping chromosomal regions, suggesting that independent genetic factors determine these fertility-related traits. The physical intervals of QTL groups were considered for possible co-location with known genes functionally involved in spike fertility traits and with yield-related QTLs previously mapped in tetraploid wheat. The most interesting result concerns a QTL group on chromosome 5B, associated with spikelet number per spike, since it could host genes still uncharacterized for their association to spike fertility. Finally, we identified two different regions where the trade-off between fertility related traits and kernel weight is overcome. Further analyses of these regions could pave the way for a future identification of new genetic loci contributing to fertility traits essential for yield improvement in durum wheat.
小麦籽粒产量是一个复杂的性状，由许多不同组成部分之间的权衡产生。在小麦进化过程中，驯化事件以及随后的现代育种通过提高穗粒育性极大地提高了小麦植株的产量潜力。为了从每穗小穗数和每小穗小花数方面研究穗粒育性的遗传基础，利用了一个由110个重组自交系（RIL）组成的群体，该群体通过将一个ssp.品种（Latino）与一个材料（MG5323）杂交获得。这两个亲本分别是现代硬粒小麦和半驯化基因型，在穗结构和育性方面存在差异，因此相应的RIL群体是剖析产量构成要素遗传基础的理想遗传材料。该RIL群体在四个环境中进行了表型分析。利用高密度SNP遗传图谱，并借助可用于的多个基因组测序结果，共鉴定出94个与所考虑的八个性状相关的QTL；基于它们的遗传和物理共定位，这些QTL进一步被归为17组。控制每小穗小花数和每穗小穗数的QTL定位在非重叠的染色体区域，这表明独立的遗传因素决定了这些与育性相关的性状。考虑了QTL组的物理区间，以确定其是否可能与已知的参与穗育性性状的功能基因以及先前在四倍体小麦中定位的与产量相关的QTL共定位。最有趣的结果涉及5B染色体上的一个QTL组，它与每穗小穗数相关，因为它可能包含尚未因其与穗育性的关联而被表征的基因。最后，我们确定了两个不同的区域，在这些区域中克服了育性相关性状与粒重之间的权衡。对这些区域的进一步分析可能为未来鉴定有助于硬粒小麦产量提高所需育性性状的新基因座铺平道路。
