Anatomical tool in the identification of ploids in maize seedlings and potential use in initial stage of double haploides obtainment process

Abstract

27Studies that optimize the haploid technique in the removal of maize lines are necessary. 28Between the stages that mostly requires attention and it is directly related to the success of 29 the technology is the correctly separation of induced haploids and diploids. Morphological 30 markers are commonly used but have strong influence of the environment, and laboratory 31 methods have been developed and may be more efficient. Thus, the objective was to study 32 the use of the anatomical analysis tool, through the analysis of young maize leaf for use as 33 the indirect markers in the identification of ploidys. The hybrids were crossed with the KEMS 34 haploid inducer. The seeds crossed, were selected according to the R-navajo marker and 35 submitted to two different protocols of chromosome duplication. Plants that survived to the 36 duplication protocols were acclimated in greenhouse and then transferred to the field. After 37 the self-polinization of the DH0 plants, the DH1 seeds were taken to the field, divided into 38 treatments according to the parentals and duplication protocols. At the vegetative stage V4 of 39 the plants, leaf tissue samples were collected to the evaluation of the amount of DNA and 40 identification of ploidys and anatomical analysis. The nuclear DNA review of each sample 41 was performed for the comparison in histograms of the position of G1 peak to the G1 peak of 42 the internal or external reference standard. A high accuracy came to validate an anatomical 43 tool, through the variables studied in this work, as a marker in the differentiation of ploidis in 44 maize plants, and it can be used in selection programs. The anatomy made in some letters is 45 a non-destructible technique and, together with a flow cytometry technique, can be used as 46 an indirect method in haploid cutting programs at the initial stage of the identification of 47 seedlings. 48 49 50 51 3 52

Doubled haploids in maize: Development, deployment, and challenges

“…Anatomical analysis (leaf blade, stomatal density, stomatal size, and photosynthesis) validated the effectiveness of these tools as effective strategy for haploid identification in maize leaves. Anatomical analysis together with flow cytometry could be used as indirect method of haploid identification at initial stages of seedling (Pires et al., 2019).…”

“…Therefore, alternative laboratory methods are more efficient for haploid screening. Pires et al (2019) explored the potential of anatomical analysis tools by analysis of young maize leaves as indirect marker for haploid identification. Anatomical analysis (leaf blade, stomatal density, stomatal size, and photosynthesis) validated the effectiveness of these tools as effective strategy for haploid identification in maize leaves.…”