Hybrid breeding in wheat: how shaping floral biology can offer new perspectives

2020 ◽  
Vol 47 (8) ◽  
pp. 675 ◽  
Author(s):  
Caterina Selva ◽  
Matteo Riboni ◽  
Ute Baumann ◽  
Tobias Würschum ◽  
Ryan Whitford ◽  
...  

Hybrid breeding in wheat (Triticum aestivum L.) has the potential to deliver major yield increases. This is a requisite to guarantee food security for increasing population demands and to counterbalance the effects of extreme environmental conditions. Successful hybrid breeding in wheat relies on forced outcrossing while preventing self-pollination. To achieve this, research has been directed towards identifying and improving fertility control systems. To maximise cross-pollination and seed set, however, fertility control systems need to be complemented by breeding phenotypically distinct male and female lines. This review summarises existing and novel male sterility systems for wheat hybridisation. We also consider the genetic resources that can be used to alter wheat’s floral development and spike morphology, with a focus on the genetic variation already available. Exploiting these resources can lead to enhanced outcrossing, a key requirement in the progress towards hybrid wheat breeding.

2019 ◽  
Vol 70 (9) ◽  
pp. 781 ◽  
Author(s):  
Jialin Guo ◽  
Gaisheng Zhang ◽  
Yulong Song ◽  
Shoucai Ma ◽  
Na Niu ◽  
...  

Multi-ovary wheat is a unique variety of wheat that has one to three pistils and three stamens, and can stably set one to three grains in each floret. By observing the developmental process of additional pistils, we found that the additional pistil was derived from a protrusion generated at the base of the main pistil, between the frontal stamen and lateral stamen. The additional pistil’s development was greatly delayed compared with the main pistil at an early stage. However, after the awn exposed stage, it developed very rapidly to a mature pistil within the maturity time of the main pistil. Generally, the grains originating from additional pistils were smaller than the grains from the main pistil. By studying the penetrance and germination conditions of multi-ovary wheat, we found that no matter which ovary the grains originated from, they had the same penetrance. However, the germination ability of grains generated from the main pistil was significantly higher than that of grains from additional pistils. Our results showed that multi-ovary wheat was an excellent variety, not only for studying the mechanisms of the multi-ovary trait and floral development in wheat, but also for improving the propagation coefficient and promoting the progress of wheat breeding. This paper lays a theoretical foundation for the practical application of multi-ovary trait in hybrid wheat; our results could be implemented in fostering future breeding activities focussed on the development of high yield wheat cultivars.


2015 ◽  
Vol 112 (51) ◽  
pp. 15624-15629 ◽  
Author(s):  
Yusheng Zhao ◽  
Zuo Li ◽  
Guozheng Liu ◽  
Yong Jiang ◽  
Hans Peter Maurer ◽  
...  

Hybrid breeding promises to boost yield and stability. The single most important element in implementing hybrid breeding is the recognition of a high-yielding heterotic pattern. We have developed a three-step strategy for identifying heterotic patterns for hybrid breeding comprising the following elements. First, the full hybrid performance matrix is compiled using genomic prediction. Second, a high-yielding heterotic pattern is searched based on a developed simulated annealing algorithm. Third, the long-term success of the identified heterotic pattern is assessed by estimating the usefulness, selection limit, and representativeness of the heterotic pattern with respect to a defined base population. This three-step approach was successfully implemented and evaluated using a phenotypic and genomic wheat dataset comprising 1,604 hybrids and their 135 parents. Integration of metabolomic-based prediction was not as powerful as genomic prediction. We show that hybrid wheat breeding based on the identified heterotic pattern can boost grain yield through the exploitation of heterosis and enhance recurrent selection gain. Our strategy represents a key step forward in hybrid breeding and is relevant for self-pollinating crops, which are currently shifting from pure-line to high-yielding and resilient hybrid varieties.


Author(s):  
M. Timothy Rabanus-Wallace ◽  
Bernd Hackauf ◽  
Martin Mascher ◽  
Thomas Lux ◽  
Thomas Wicker ◽  
...  

AbstractWe present a chromosome-scale annotated assembly of the rye (Secale cereale L. inbred line ‘Lo7’) genome, which we use to explore Triticeae genomic evolution, and rye’s superior disease and stress tolerance. The rye genome shares chromosome-level organization with other Triticeae cereals, but exhibits unique retrotransposon dynamics and structural features. Crop improvement in rye, as well as in wheat and triticale, will profit from investigations of rye gene families implicated in pathogen resistance, low temperature tolerance, and fertility control systems for hybrid breeding. We show that rye introgressions in wheat breeding panels can be characterised in high-throughput to predict the yield effects and trade-offs of rye chromatin.


1981 ◽  
Vol 23 (2) ◽  
pp. 337-348 ◽  
Author(s):  
Seiichi Tsuji ◽  
S. S. Maan

Alloplasmic Triticum aestivum L. cv. Selkirk lines having cytoplasms of five D-genome Aegilops species were crossed reciprocally with euplasmic T. durum Selection 56-1 to study differential cytoplasmic effects on pentaploid hybrids. Pollen fertility of the alloplasmic and euplasmic pentaploid hybrids ranged from 23.0% to 46.6%, and from 84.9% to 91.1%, respectively. Significant differences in seed-set and in the viability of backcrossed seed were observed between the euplasmic and alloplasmic pentaploids as well as among the five alloplasmic pentaploids. The pentaploid with Ae. squarrosa cytoplasm did not transmit 14-chromosome male gametes. The cytoplasms of Ae. squarrosa, Ae. cylindrica and Ae. ventricosa were similar to one another in their differential effects on the transmission of euploid and aneuploid male gametes numbers, and similarly the cytoplasms of Ae. crassa and Ae. juvenalis resembled each other.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Amanda C. Easterly ◽  
Walter W. Stroup ◽  
Nicholas Garst ◽  
Vikas Belamkar ◽  
Jean-Benoit Sarazin ◽  
...  

AbstractHybrid wheat (Triticum spp.) has the potential to boost yields and enhance production under changing climates to feed the growing global population. Production of hybrid wheat seed relies on male sterility, the blocking of pollen production, to prevent self-pollination. One method of preventing self-pollination in the female plants is to apply a chemical hybridizing agent (CHA). However, some combinations of CHA and genotypes have lower levels of sterility, resulting in decreased hybrid purity. Differences in CHA efficacy are a challenge in producing hybrid wheat lines for commercial and experimental use. Our primary research questions were to estimate the levels of sterility for wheat genotypes treated with a CHA and determine the best way to analyze differences. We applied the CHA sintofen (1-(4-chlorphyl)-1,4-dihydro-5-(2-methoxyethoxy)-4-oxocinnoline-3-carboxylic acid; Croisor 100) to 27 genotypes in replicate. After spraying, we counted seed in bagged female heads to evaluate CHA efficacy and CHA-by-genotype interaction. Using logit and probit models with a threshold of 7 seeds, we found differences among genotypes in 2015. Sterility was higher in 2016 and fewer genotypic differences were found. When CHA-induced sterilization is less uniform as in 2015, zero-inflated and hurdle count models were superior to standard mixed models. These models calculate mean seed number and fit data with limit-bounded scales collected by agronomists and plant breeders to compare genotypic differences. These analyses can assist in selecting parents and identifying where additional optimization of CHA application needs to occur. There is little work in the literature examining the relationship between CHAs and genotypes, making this work fundamental to the future of hybrid wheat breeding.


2020 ◽  
Author(s):  
Hongsheng Li ◽  
Shaoxiang Li ◽  
Sedhom Abdelkhalik ◽  
Armaghan Shahzad ◽  
Jian Gu ◽  
...  

Abstract Background: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is now a dominant and promising approach of wheat heterosis utilization in China. However, during past twenty years only several TPSGMS lines have been capable of practical application in hybrid wheat breeding and production, which reduced the opportunities and efficiency of creating hybrids with strong heterosis. Introducing doubled haploid (DH) breeding could be a helpful strategy to efficiently develop practically usable TPSGMS lines. Results: F 1 s and selected F 2 and F 3 sterile plants from eight crosses made from two commercial TPSGMS lines were used to produce DH lines by using the wheat × maize system. Twenty four elite sterile lines possessing stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, and desirable plant height (50-60 cm) were obtained within 4 years through at least one year evaluation. Twenty from twenty four elite lines showed stable sterility in repeated tests of two or three years, will be selected for hybrid breeding. The percentage of elite lines within total tested DH lines produced from filial generations was in the order of F 2 > F 3 > F 1 in this study. Conclusions: Our study shows that DH breeding is more efficient for the selection of traits controlled by recessive gene(s) compared with conventional breeding, especially for the sterility of TPSGMS wheat. Coupling DH techniques with conventional breeding would be an efficient strategy for developing practically usable wheat TPSGMS lines in respect to number and saving time, which is helpful for further improving the efficiency of wheat hybrid breeding. Producing DHs from F 2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1244
Author(s):  
Zachary James Winn ◽  
Dylan Lee Larkin ◽  
Jamison Trey Murry ◽  
David Earl Moon ◽  
Richard Esten Mason

Phenotyping wheat (Triticum aestivum L.) is time-consuming and new methods are necessary to decrease labor. To develop a heterotic pool of male wheat lines for hybrid breeding, there must be an efficient way to measure both anther extrusion and the size of anthers. Five hundred and ninety-four soft red winter wheat lines in two replications of randomized complete block design were phenotyped for anther extrusion, a key trait for hybrid wheat production. A device was constructed to capture images using a mobile device. Four heads were sampled per line when anthesis was evident for half the heads in the plot. The extruded anthers were scraped onto a surface, their image was captured, and the area of the anthers was taken via ImageJ. The number of anthers extruded was estimated by counting the number of anthers per image and dividing by the number of heads sampled. The area per anther was taken by dividing the area of anthers per spike by the number of anthers per spike. A significant correlation (R=0.9, p<0.0001) was observed between the area of anthers per spike and the number of anthers per spike. This method is proposed as a substitute for field ratings of anther extrusion and to quantitatively measure the size of anthers.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 815
Author(s):  
Sandra V. Rojas-Nossa ◽  
José María Sánchez ◽  
Luis Navarro

Floral development depends on multifactor processes related to genetic, physiological, and ecological pathways. Plants respond to herbivores by activating mechanisms aimed at tolerating, compensating, or avoiding loss of biomass and nutrients, and thereby survive in a complex landscape of interactions. Thus, plants need to overcome trade-offs between development, growth, and reproduction vs. the initiation of anti-herbivore defences. This study aims to assess the frequency of phloem-feeding herbivores in wild populations of the Etruscan honeysuckle (Lonicera etrusca Santi) and study their effects on floral development and reproduction. The incidence of herbivory by the honeysuckle aphid (Hyadaphis passerinii del Guercio) was assessed in three wild populations of the Iberian Peninsula. The effect of herbivory on floral morphology, micromorphology of stigmas and pollen, floral rewards, pollination, and fruit and seed set were studied. The herbivory by aphids reduces the size of flowers and pollen. Additionally, it stops nectar synthesis and causes malformation in pollen and microstructures of stigmas, affecting pollination. As a consequence, fruit set and seed weight are reduced. This work provides evidence of the changes induced by phloem-feeding herbivores in floral development and functioning that affect the ecological processes necessary to maintain the reproductive success of plants.


Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 165
Author(s):  
Allan Waniale ◽  
Rony Swennen ◽  
Settumba B. Mukasa ◽  
Arthur K. Tugume ◽  
Jerome Kubiriba ◽  
...  

Seed set in banana is influenced by weather, yet the key weather attributes and the critical period of influence are unknown. We therefore investigated the influence of weather during floral development for a better perspective of seed set increase. Three East African highland cooking bananas (EAHBs) were pollinated with pollen fertile wild banana ‘Calcutta 4′. At full maturity, bunches were harvested, ripened, and seeds extracted from fruit pulp. Pearson’s correlation analysis was then conducted between seed set per 100 fruits per bunch and weather attributes at 15-day intervals from 105 days before pollination (DBP) to 120 days after pollination (DAP). Seed set was positively correlated with average temperature (P < 0.05–P < 0.001, r = 0.196–0.487) and negatively correlated with relative humidity (RH) (P < 0.05–P < 0.001, r = −0.158–−0.438) between 75 DBP and the time of pollination. After pollination, average temperature was negatively correlated with seed set in ‘Mshale’ and ‘Nshonowa’ from 45 to 120 DAP (P < 0.05–P < 0.001, r = −0.213–−0.340). Correlation coefficients were highest at 15 DBP for ‘Mshale’ and ‘Nshonowa’, whereas for ‘Enzirabahima’, the highest were at the time of pollination. Maximum temperature as revealed by principal component analysis at the time of pollination should be the main focus for seed set increase.


1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.


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