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Genetic Resources and Crop Evolution

, Volume 66, Issue 8, pp 1727–1760 | Cite as

Comparative assessment of einkorn and emmer wheat phenomes: III. Phenology

  • Abdullah A. JaradatEmail author
Research Article
  • 58 Downloads

Abstract

In-depth information on plant phenology of einkorn (Triticum monococcum L. subsp. monococcum) and emmer, (Triticum turgidum subsp. dicoccun (Schrank) Thell) germplasm is indispensable for better utilization of their available genetic resources as underutilized crops, especially under abiotic stress. Whereas; optimization of their phenology is one of the most effective strategies to achieve this goal as it is a key factor for crop adaptation under abiotic stress. The objectives of this study were to integrate quantitative phenotyping methods to describe and explain phenotypic and genotypic differences or similarities in phenological stages within vegetative and reproductive growth phases between einkorn and emmer germplasm; identify combinations of discriminating traits between einkorn and emmer germplasm at successive phenological growth stages; and estimate multivariate distances between einkorn and emmer germplasm based on their geographical sources and stage of genetic improvement. The evaluated germplasm represented a wide range of geographical origins in the Fertile Crescent of West Asia, East Africa, West and East Europe, and North America. The study developed a method for accurate estimation of synchrony and duration of phenological growth stages of the diverse germplasm; and presented a ‘sliding’ scale capable of discriminating between different ‘maturity classes’ of the species on the basis of five phenology indicators, vis: growing degree days in conjunction with plant height, normalized difference vegetative index, color space coordinates, and green gradient-based canopy segmentation. Reliable relationship was established between visual scoring and color measurements of plants based on digital images at different growth stages. This relationship may become useful for research and crop management in resource-limited areas. Accurate prediction of phenological growth stages of einkorn and emmer wheat is essential, not only for ideotype development through simulation and modeling of weather and management effects, but also to help establish a cottage industry to benefit small-scale farmers, and to improve and maintain high-quality end products from these underutilized wheat genetic resources.

Keywords

Hulled wheats Growth phases Growth stages Phenological indicators 

Abbreviations

a

Green (negative)–Reddish (positive) color space coordinate

b

Blueish (negative)–Yellowish (positive) color space coordinate

BT

Boosted trees

CFA

Confirmatory factor analysis

C:N

Carbon-to-nitrogen ratio

CIELab

Combined color space coordinates

ECa

Apparent soil electrical conductivity (dS m−1)

EGV

Early growth vigor

GCV

Genotypic coefficient of variation

GDD

Thermal time in growing degree days

GFP

Grain filling period

GS31

Early stem elongation stage

GS39

Late stem elongation stage

GS49

Booting stage

GS57

Heading stage

GS65

Anthesis stage

GS89

Physiological maturity stage

GYI

Grain yield index

h2

Narrow-sense heritability estimate

L

Dark (zero)–White (100) color space coordinate

Lab

Color space coordinates (i.e., combined estimates of L, a, and b, above)

MDS

Multi-dimensional scaling

NDVI

Normalized difference vegetation index

PGR

Plant genetic resources

PH

Plant height

PTQ

Photothermal quotient

PC

Principal component

PCV

Phenotypic coefficient of variation

PLSR

Partial least squares regression

RGB

Red, green, blue light spectrum

RMA

Reduced major axis

RUE

Radiation use efficiency (g MJ−1)

SI

Senescence index

SPAD

Soil plant area development

SG

Stay green

SVM

Support vector machine

Notes

Acknowledgements

This research was supported by USDA Project Number 5060-21220-005-D. Thanks are due to support staff at the North Central Soil Conservation Research Lab., Morris, MN. USDA is an equal-opportunity provider and employer.

Funding

This study was funded by USDA Project Number: 5060-21220-005-D.

Compliance with ethical standards

Conflict of interest

The author declares that he has no conflict of interest.

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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.USDA-ARSMorrisUSA
  2. 2.Department of Agronomy and Plant GeneticsUniversity of MinnesotaSt. PaulUSA

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