da Silva Jean Paulo Aparecido, Viana José Marcelo Soriano, Dias Kaio Olimpio das Graças, Silva Jéssica Coutinho, Tupper Vivian Torres Bandeira, Clarindo Wellington Ronildo
Department of General Biology, Federal University of Viçosa, Viçosa, Brazil.
Front Plant Sci. 2023 May 30;14:1176504. doi: 10.3389/fpls.2023.1176504. eCollection 2023.
For popcorn, obtaining and identifying haploids are still challenging steps. We aimed to induce and screen haploids in popcorn using the Navajo phenotype, seedling vigor, and ploidy level. We used the Krasnodar Haploid Inducer (KHI) in crosses with 20 popcorn source germplasms and five maize controls. The field trial design was completely randomized, with three replications. We assessed the efficacy of induction and identification of haploids based on the haploidy induction rate (HIR) and false positive and negative rates (FPR and FNR). Additionally, we also measured the penetrance of the Navajo marker gene (). All putative haploids classified by the were germinated together with a diploid sample and evaluated for false positives and negatives based on vigor. Seedlings from 14 females were submitted to flow cytometry to determine the ploidy level. The HIR and penetrance were analyzed by fitting a generalized linear model with a logit link function. The HIR of the KHI, adjusted by cytometry, ranged from 0.0 to 1.2%, with a mean of 0.34%. The average FPR from screening based on the Navajo phenotype was 26.2% and 76.4% for vigor and ploidy, respectively. The FNR was zero. The penetrance of ranged from 30.8 to 98.6%. The average number of seeds per ear in temperate germplasm (76) was lower than that obtained in tropical germplasm (98). There is an induction of haploids in germplasm of tropical and temperate origin. We recommend the selection of haploids associated with the Navajo phenotype with a direct method of confirming the ploidy level, such as flow cytometry. We also show that haploid screening based on Navajo phenotype and seedling vigor reduces misclassification. The origin and genetic background of the source germplasm influence the penetrance. Because the known inducers are maize, developing doubled haploid technology for popcorn hybrid breeding requires overcoming unilateral cross-incompatibility.
对于爆裂玉米而言，获得和鉴定单倍体仍然是具有挑战性的步骤。我们旨在利用纳瓦霍表型、幼苗活力和倍性水平在爆裂玉米中诱导和筛选单倍体。我们将克拉斯诺达尔单倍体诱导系（KHI）与20份爆裂玉米源种质和5份玉米对照进行杂交。田间试验设计为完全随机，重复三次。我们基于单倍体诱导率（HIR）以及假阳性和假阴性率（FPR和FNR）评估单倍体的诱导和鉴定效果。此外，我们还测量了纳瓦霍标记基因的外显率。所有通过[具体方法]分类的假定单倍体与一个二倍体样本一起萌发，并根据活力评估假阳性和假阴性。来自14个雌性植株的幼苗进行流式细胞术检测以确定倍性水平。通过拟合具有logit连接函数的广义线性模型分析HIR和外显率。经流式细胞术校正后，KHI的HIR范围为0.0%至1.2%，平均值为0.34%。基于纳瓦霍表型筛选的平均FPR在活力和倍性方面分别为26.2%和76.4%。FNR为零。外显率范围为30.8%至98.6%。温带种质的每穗平均种子数（76粒）低于热带种质（98粒）。在热带和温带起源的种质中都有单倍体的诱导。我们建议选择与纳瓦霍表型相关的单倍体，并采用直接确认倍性水平的方法，如流式细胞术。我们还表明，基于纳瓦霍表型和幼苗活力的单倍体筛选可减少错误分类。源种质的起源和遗传背景影响[具体基因]的外显率。由于已知的诱导系是玉米，为爆裂玉米杂交育种开发双单倍体技术需要克服单向杂交不亲和性。
