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Advances in the Exploitation of Xenia and Metaxenia in Fruit and Nut Crops
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Advances in Horticulture Crops and Their Challenges
Volume-1
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Chapter-4
Shikha Saini, Bhupendra Sagore, Shikha Jain and Poonam Maurya Abstract
The term "xenia" describes a phenomenon in which the genotypes of pollen directly influence the phenotypic qualities of fruits and seeds from fertilisation to seed germination. The xenia effect can alter various fruit parameters, including the fruit ripening period, the fruit shape, size, and colour, the flavour quality, such as sugars and acids, as well as the nutrient quality, such as anthocyanins. It can also cause differences in the embryo and endosperm formed after double fertilisation. The two types of xenia now recognised are xenia and metaxenia. In the former, pollen genotype directly affected syngamous tissues (embryo and endosperm), but in the later, pollen genotypes had an impact on maternal tissues. The xenia impact appears in many different ways, contributing significantly to increased production, enhanced fruit quality, and improved fruit appearance. The xenia and metaxenia have been described in many fruits, such as apples, date palm, blueberries, almond, walnut, chestnut, macadamia nut, pomegranate and kiwifruit etc. In earlier research, it was proposed that the observed cases of metaxenia may be caused by hormone-related pollen parent effects, enzyme activities, or mRNA action hypotheses. Over the past century, advances in molecular biology have opened up new possibilities for researching the mechanism of xenia.Lack of knowledge about pollen source and mechanism responsible for xenia effect limits its exploitation.
Further, in some fruit crops, there is non-synchronization of flowering and thus, controlled pollination in vigorous trees is cumbersome and requires time, labour and resources, which increases the cost of production. Our understanding of xenia and metaxenia is still in infancy phase. Research is needed to investigate pollen parent effects, suitable female/pollen-parent combinations and their mode of action in all fruit and nut crops that will utilize these beneficial xenic effects.
Keywords: Embryo, endosperm, pollen, metaxenia, xenia, mRNA Introduction
Fruit formation requires several prerequisites, including pollen source, seed set, and subsequent fruit growth. The genotype of the pollinator in particular can have a marked effect on fertilisation and consequently seed set. Pollination is the transfer of pollen from a plant's male reproductive components to its female reproductive components for seed set and fruit development. Pollination, followed by fertilization is the essential processes for fruit set. It can be cross where pollen is from genetically different plant
Advances in the Exploitation of Xenia and
Metaxenia in Fruit and Nut Crops
52
and self when the plants are able to bear fruits without any outsider pollen. Among cross pollination, the effect of pollen has been discussed under hybridization and xenia/metaxenia. In hybridization, pollen parent effect is measured in the next generation i.e. in F1 generation, whereas in case of xenia/metaxenia the pollen gives immediate impact of pollen parent on female parent, which is observed during pollination i.e. in the F0 generation. The xenia effect appears in many different ways, contributing significantly to directional breeding as well as enhancing fruit yield, improving fruit appearance, and internal fruit and nut quality. Our knowledge of the xenia impact is still developing in comparison to other pomology research topics. Xenia and metaxenia are two categories into which it is now divided. In the former, only the syngamous portions of the ovules—the embryo and endosperm—show the direct impacts of the pollen genotype. The latter shows how the pollen genotype affects structures other,than the embryo and endosperm, such as tissues made entirely of mother plant material, seed portions like the nucellus and testa, and even the carpel and accessory tissues (Yang et al., 2020).
Xenia
The term ‘Xenia’ was coined by Wilhem Olbers Focke in 1881 as the pollen induced changes in mother tissues. Before it was discovered that angiosperms may undergo double fertilization, the word,was first used to explain how pollen affects endosperm during a period when endosperm was thought to be solely a maternal tissue. The definitions of these two words, xenia and metaxenia, are frequently ambiguous.
Numerous xenia and metaxenia definitions directly contradict one another. There are numerous definitions of xenia provided by scientists and experts. Swingle (1992) in his studies divides xenia and metaxenia on the basis of effect on syngamous tissues and maternal tissues. The pollen parent effect is on syngamous tissues i.e. on embryo and endosperm then it is defined as xenia. Moreover, Westwood (1989) stated xenia as physiological effect of foreign pollen on maternal tissues. Denney (1992) defined xenia as the pollen induced changes in seed and fruit shape, colour, ripening time and chemical composition. Denney covered all changes induced by pollen parent under xenia.
According to Denney, classification of xenia based on various discernible characteristics makes it clearer to understand xenia as compared to the classification based on syngamous vs. non-syngamous tissues. They gave several terms, such as xenoplasm (changes the fruit shape), xenochroms (changes in fruit color), xenochrons (changes in developmental timings like ripening or maturing period), xenochems (changes in the chemical composition of seed and fruit) and xenodoches (changes in the fruit size).
Metaxenia
The impact of pollen on fruit traits (pericarp colour, shape and chemical composition etc.) is known as metaxenia. In plantings of mixed cultivars, it would be
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possible to utilize it to determine the best pollinizer parents in order to shorten the fruit development period (FDP) and boost yield. Swingle (1928) suggested the term metaxenia and defined it as ‘the immediate effect of pollen on maternal tissues. Denney (1992) further cleared that xenia is including metaxenia and it is a special case of xenia where only maternal tissues are affecting. Pollen source that directly affects the fruit shape, maturation period, size, colour, flavor and content of substances is termed as xenia. However, this form of development is better explained in a manner other than xenia.
History of xenia/metaxenia
Xenia is first observed in maize (Zea mays) and it is very conspicuous in maize grains. As in some varieties the endosperm is yellowish in color while in others it is white. Genetically yellow color is dominant over white color and the appearance of xenia depends upon whether or not the endosperm characters of the male parent are dominant over the female parent. The pollination of white endospermic varieties with yellow endospermic pollens gives seeds with yellow endosperm. On the other hand, if yellow endospermic varieties (male parent is recessive); even then the seeds with yellow endosperm are formed (Fig. 1). There is no apparent effect of xenia.
The effect of pollen grains is not only restricted to the characters of the endosperm. They also have an impact on tissues outside the endosperm, such as seed coat, fruit flesh and peel. This effect of pollen grains is known as metaxenia. In Pheonix dactylifera, the size and time of maturity of fruits depend on the type of pollen grains fertilizing the ovules. There is a secretion of certain hormones or similar substances by endosperm or embryo or both, which diffuse out into the wall of the seed and fruit and exert specific effect. The secretion of these substances is influenced by the pollen grains which fertilize the ovules.
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Fig. 1: The ears of white maize cross pollinated by foreign pollen of neighbouring yellow maize from the first adjoining row to the pollen source to the 19th row as compared with the pure white and yellow maize rows(Parents) indication effects of xenia (Ma et al., 2004).
The mechanisms behind xenia and metaxenia
The idea of xenia can be understood easily through the process of double fertilization, in which the male and female gametes combine to produce the diploid zygote (2n), and the male and female gametes combine to form the endosperm (3n).
Consequently, xenia is the result of the genes from the male parent influencing the endosperm and embryonic development. The direct effect of pollen on the seed may be explained by double fertilization, however this does not account for pollen's effects on the fruit outside of the embryo and endosperm. The metaxenia effect has been explained by a number of different theories. Transposons had previously been thought of as potential candidates for the underlying cause of many xenia phenomena. Transposons, however, can only travel within chromosomes. They don't “jump” from maternal tissue to syngamous tissue.
Imprinting is a phenomenon that Kermicle (1978) defined as the preferred expression of genes based on whether they were inherited from the paternal or maternal side. Paternal imprinting can clearly influence maize kernel size and endosperm development, which explains some cases of xenia.Higher plants experience this imprinting, also known as parent-specific gene expression (PSGE). Although the idea that PSGE resolves genetic conflict between mother and father is widely accepted, de Jong and Scott (2007) claim that the conditions for PSGE to develop are restricted.
PSGE progresses in terms of seed size only when the developing offspring has a large impact on its own resource acquisition.
The past century's advances in molecular biology have opened up new possibilities for investigating the xenia process. Traditionally, RNA molecules were assumed to work exclusively within the cell in which they are produced. However, recent research shows that in addition to this traditional function, RNA also functions as a non cell- autonomous signal molecule that moves between cells to control gene expression in distant target regions.Endogenous mRNA molecules have been shown by Kim et al.
(2001) to not only move across plant cells but also have the capacity to impact the phenotype of developing tissue. Additionally, Kudo and Harada (2007) demonstrated how a tomato rootstock lacking leaves might alter the potato leaf's shape. Even more interestingly, plant male gametes have also been found to contain mRNAs, in addition to mammalian spermatozoa. For instance, Engel et al. (2003) demonstrated that Zea mays sperm cells have a,complex complement of mRNAs. It has been proposed that RNAs, particularly mRNA and small RNAs, may be present in Darwin's supposed gemmules (Liu, 2006). According to these observations, pollen releases mRNAs during
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fertilisation, which diffuse into the mother plant's tissues. Once inside, the translocated mRNAs alter the size, shape, colour, timing of development, and chemical makeup of seeds and fruits, varying depending on the particular male parent.
Hormonal action theory for metaxenia
The simplest and most likely theory to explain metaxenia, according to Swingle (1928), is that the embryo or endosperm, or both, secrete hormones or soluble substances analogous to them. These substances diffuse out into the mother plant's tissues that constitute the seed and fruit and there they exert a specific effect on these tissues, varying depending on the specific male parent used to fecundate the embryo and endosperm. Pollen grains have an impact on more than only the endosperm's characteristics; they also have an impact on tissues beyond the endosperm, such the seed coat, etc. This effect of pollens is known as “metaxenia”. The size and timing of fruit maturity in Pheonix dactylifera are influenced by the type of pollen grains fertilizing the ovules. Endosperm, embryo, or both secrete various hormones or comparable chemicals that,diffuse into the seeds,and fruit wall,and have a specific impact. The pollen grains that fertilize the ovules have an impact on the release of these chemicals in turn.
Novel Classification forms of xenia
The tissue created by xenia may or may not have received paternal information through double fertilization, depending on how xenia and metaxenia are now classified.
Additionally, it gives no indication of the xenia's underlying cause. The physiological mechanisms of the production of the organs and tissues that exhibit xenia must thus be investigated in order to advance xenia research, with a particular focus on determining if the emergence of xenia was caused by tissue created by double fertilization.
Accordingly, Yang et al. (2020) gives a revised classification of xenia into three types:
double fertilization xenia, non-double fertilization xenia, and combination xenia. This new classification of xenia may have significant theoretical and practical implications for future study of xenia and its mechanisms, as well as for a more widespread and successful application of xenia to improve fruit tree quality and productivity.
i. Double-Fertilization Xenia
Double-fertilization xenia refers to the phenomenon where the pollen transfers genetic information from male,parent through the double-fertilized tissues (embryo or endosperm) in the period from fertilization to germination of seeds, causing changes in the embryo, endosperm, and seed-coat, and in the fruit developmental period, fruit size, shape, flavour colour, and nutrient content.
ii. Non-Double Fertilization Xenia
Non–double-fertilization xenia refers to the phenomenon where the information from the male,parent is transferred by pollen grains through non-double, or single,
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fertilization pathways during the time period from fertilization to germination of seeds, causing changes in the embryo, endosperm, and seed-coat, and in the fruit developmental period, fruit size, shape, flavour, pericarp colour, and nutrient content.
iii. Combined Xenia
Combined xenia refers to the phenomenon where the information from the male parent is transferred by pollen grains through thedouble-fertilized tissue (embryo or endosperm) and non–double-fertilized tissuesduring the time period from fertilization to germination of seeds, causing changes in the embryo, endosperm, and seed-coat, and in the fruit developmental period, fruit size, shape, flavour, pericarp colour, and nutrient content.
Advantages of xenia and metaxenia in fruit crops
The impact of xenia on the production of fruits and seeds, as well as applications in plant breeding and increasing grain yield or fruit size and quality, is of significant agronomic importance (Pozzi et al., 2019).
▪ Increase the fruit weight, size and shape etc.
▪ Improve the fruit appearance and quality (colour, sweetness and flavours etc.)
▪ Change in developmental timings (maturity period, flowering period or ripening period etc.)
▪ Change in chemical composition (anthocyanins, sugar content and acids etc.)
▪ Increase copra content in coconuts.
▪ Reduce the bitterness of kernels in almonds.
▪ Increase oil content in fruit nut crops.
▪ Increase kernel size and alter biochemical composition in fruit nuts.
Thus, studying the effect of xenia has great significance in fruit crops where fruit and seeds are the main targets for harvest.
Effects of xenia and metaxenia in fruit and nut crops
Date palm: The date palm (Phoenix dactylifera L.) is dioecious, subtropical fruit tree and native to Iraq. The female inflorescence is hand pollinated with pollen from selected males in commercial plantations. It is very well known to the date growers that pollen from different sources has an immediate impact on the properties of seeds and fruits of date palm. Pollen sources from different date affects ripening time, color, weight, size and other qualities of the date palm fruit (Farag, 2005; Shafique et al., 2011). Fruits fertilized by pollens from Phoenix canariensis recorded the highest values in most
“Khalas” fruit quality indicators to boost production, fruit quality, and early fruit ripening for approximately 2 weeks. (Khalil Omar et al. 2014). Munir et al. (2020) also reported superior results regarding fruit set percentage, tamar fruit percentage, bunch weight, pulp weight, fruit moisture content and TSS content was observed when khalas cultivar was pollinated with an indigenous pollinizer.
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Apple: The majority of apple cultivars are self-incompatible thus, cross pollination is critical in successful apple cultivation.Few studies have investigated the direct impact of pollen source on apple fruit quality and return bloom i.e. xenia and metaxenia in apple. The pollen's metaxenia effect helps in the selection of apple pollinizer cultivars to improve fruit quality. The fruit set, quantity of viable seeds per fruit, flesh hardness, skin colour, and fruit weight are all affected by different pollen sources(Militaru et al., 2015). The flavor and aroma of the fruits produced by the "Fuzi" apple tree when pollinated by several pollinizer varieties differed significantly (Wang et al., 2017). The quince pollen (Cydonia oblonga) significantly altered the fruit weight, fruit firmness, Vitamin C content, sugar-acid ratio, total phenolics, and total flavonoids of apple cultivars, resulting in increased fruit quality (Zhang et al., 2019). The choice of an appropriate pollinator before planning an orchard can enhance fruit appearance and quality.
Coconut: The most valuable commercial component of coconuts is the dried endosperm known as copra, and oil can be produced from copra by crushing it.Results of investigations made on nut and copra characters indicated xenia effect in coconut where pollens from large nuts gives increased copra content in small nut cultivars (Luckanatinvong and Sirphanich, 2016). A very good example of xenia in coconut has been observed in kopyor coconuts. In Indonesia, the Kopyor coconut, a rare coconut mutant, is highly valuable economically (Fig.2). The abnormal, soft, and fluffy endosperm of kopyor coconuts is one of its distinguishing features.The genotype of the kopyor coconut endosperm is kkk and normal coconut endosperm will be homozygous KKK or heterozygous KKk and Kkk. In order to improve Kopyor coconut yield, it was proposed to plant homozygous kk Kopyor coconut trees rather than the normal homozygous KK & heterozygous Kk coconut trees (Ismail et al., 2016).
Fig. 2: Normal and Kopyor coconut
Dragon fruit (Hylocereus sp.): The flowers of cultivated vine cacti from the genera Hylocereus and Selenicereus must be manually pollinated due to self-incompatibility and a lack of efficient pollinators. Stigmas were added to the Hylocereus polyrhizus flowers after they had been pollinated by diverse pollen sources on the same day.
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Flowers of Hylocereus polyrhizus pollinated with Selenicereus grandiflorus and S.
megalanthus pollen delayed fruit ripening by 1 and 3 weeks respectively in compared to fruits fertilized with Hylocereus undatus pollen (Fig. 3). The pollen source had a substantial impact on fruit size, pulp dry weight, and the number of seeds per fruit, while S. megalanthus pollen markedly enhanced peel dry weight (Mizrahi et al., 2004). The results demonstrate metaxenia, or the effect of pollen on maternal tissues, in cacti fruits.
The market life of H. polyrhizus fruits may be extended by taking advantage of this pollen effect on fruit ripening time.
Fig. 3: Hylocereus polyrhizus branch bearing two fruits at different stages of ripening.
The red, ripe fruit originated from pollination with pollen of H. undatus clones, while the green, unripe fruit was from pollination with S. grandiflorus pollen.
Pomegranate: Numerous studies have shown that pollen sources directly affect the fruit and seed characteristics of the maternal plant. The internal and external quality characteristics of pomegranate fruits may be influenced by pollen sources. When pollinated by "Rabab Neyriz," "Poost Sefid Dezful," and "Malas Pishva Varamin," the fruit set, fruit quality features, aril qualities, seed characteristics, and edible portion of the female cultivar "Malas Yazdi" (Fig. 4) have changed as a result of metaxenic effects (Gharaghani et al., 2017).
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Fig.4: The effects of pollen sources from ‘Rabab Neyriz’, ‘Poost Sefid Dezful’, and
‘Malas Pishva Varamin’ on the peel and aril colour of ‘Malas Yazdi’ pomegranate
Table 1: Effects of xenia and metaxenia in fruit crops.
Species Phenotypic characteristics of xenia and metaxenia
References
Grape High berry set percentage, increased weight, lenght and width of berry and number of seeds per berry
Sabir, 2015
Annona sp.
Increased fruit set, quicker fruit maturity, large fruit shape and symmetrical fruits
Jalikop and Kumar, 2007 Olive Increased fruit weight, fruit size, seed
weight, pulp weight and double seed fruit production.
Hui et al., 2016;
Gharaghani et al., 2017
Kiwifruit Average fruit weight, fruit biochemical characteristics and seed weight, number and protein content
Stasiak et al., 2019
Guava Fruit size, shape, weight and quality Usman et al., 2013
Kiwifruit: Kiwifruit (Actinidia sp.) belong to the family Actinidiaceae is native of China.There is some evidence that a variety of significant commercial fruit characteristics in Kiwifruit can be impacted by the selected pollen donor.In kiwifruit, flowers of diploid Actinidia chinensis were hand pollinated with diploid A. chinensis cultivar ‘Bruce’ and A. deliciosa which is hexaploid. Fruits having fully developed seeds with anthocyanin production in core were observed in case when pollen parent is diploid A. chinensis (Fig. 5) and fruits having poorly developed seeds without redness in the core were observed when it was pollinated with hexaploid A. deliciosa (Seal et al., 2013).
Almonds: Numerous nut crops are known to experience pollen parent effects on kernel and nut properties in addition to fruits. According to reports, sweet pollinators in almond are said to reduce amygdalin levels and, as a result, bitterness. Pollen parents modify the ratios of oleic and linoleic acids, which has an impact on the oil quality in addition
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to the kernel's size and weight. According to reports, the sweet pollinizer in almonds lowers amygdalin levels and lessens bitterness by up to 21% (Sanchez-Perez et al., 2012) .Parents who had huge nuts and kernels had an impact on the recipient parent's nuts and kernels (Majid et al., 2020). The oil quality was influenced by the kind of pollen source and its altered oleic/linoleic acid ratio. When fertilized with "Filip Ceo"
pollen, "Shahrood 12" had the greatest oleic/linoleic acid ratio i.e. 8.35% (Alizadeh- Salte et al., 2018).
Fig. 5: A & C: Seed and red flesh colour development after pollination with pollen from A. chinensis ‘Bruce’
B & D: Poor seed and anthocyanin development after pollination with pollen from hexaploid A. deliciosa(Seal et al., 2013)
Hickory(Carya cathayensis): The Juglandaceae family includes hickory (Carya cathayensis) and pecan nut (Carya illinoinensis K. Koch). In China, hickory is a major and widely cultivated nut tree. The varied hickory and pecan fruit characteristics, such as different maturation times, sizes, and kernel compositions, give growers the possibility to cross these two species. Hickory has experienced the effects of interspecific pollination, but molecular research has revealed that metaxenia is present and that these effects are not the result of genetic modifications. The pollination of the hickory trees with pecan nuts, which produces the metaxenia photosynthetic mechanism, resulted in the larger and greener hickory fruits (Fig. 6). The pecan nut (Carya illinoinensis) pollen accelerates the buildup of dry matter and the generation of oil in hickory fruit. In pecan nuts, there is better coordination between the up-regulation of chlorophyll concentration, rubisco activity, and nitrogen content (Huang et al., 2020).
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Fig.6: Differences at different fruit growth stage in the appearance between hickory (C.
cathayensis) fruits developed after intraspecific hickory pollination (ph fruits) and after interspecific pollination by pecan pollens (pp fruits).
Table 2: Effect of xenia and metaxenia in other nut crops
Species Phenotypic
characteristics of xenia
References
Persian walnut Nut size, kernel diameter, kernel weight, thickness, total proteins and fat content of kernels
M. Golzari et al., 2016
Chestnut (C.
mollissima BL.)
Fruit size, starch content, pyruvate phosphate dikinase, photosynthesis
Liang et al., 2016
Henry chestnut (Castanea henryi)
Soluble sugars, fats, proteins, amylase, Vitamin C
Zhang et al.,2016 Macadamia (M.
ternifolia)
Nut mass, kernel mass, kernel recovery
Herbert et al., 2019 Hazelnut Final fruit setting, kernel and
nut weight, kernel percentage,number of blank nuts
Balik and Beyhan, 2019
Limitations in Exploiting Xenia and Metaxenia in Fruit Crops
▪ The mechanisms of xenia and metaxenia are not clearly understood.
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▪ There are very few studies on the physiological and molecular mechanisms behind xenic effects.
▪ There is a scarcity of data on the negative or less desirable effects of xenia and metaxenia.
▪ Lack of knowledge about pollen sources.
▪ Controlled pollination in cross-pollinated and vigorous fruit crops is cumbersome and labour-intensive.
▪ Non-synchronization of flowering in some fruits and nut crops requires artificial pollination for effective pollination.
Future line of work
▪ There is a need for an exhaustive study to know the male parents (pollen sources) with beneficial xenia effect on maternal genotypes in fruit crops.
▪ Expression of xenia/metaxenia effects under varying agro-climatic conditions needs to be investigated.
▪ We need to determine the physiological and genetic bases of xenia and metaxenia for qualitative and quantitative characteristics in fruit and nut crops.
Conclusion
Xenia and metaxenia helps in improvement of fruit and seed quality (physical as well as chemical), size and shape, reduce the bitterness, and increase the oil content.
As most of the fruit and nut crops require pollinizers being self-incompatible or dichogamous for sufficient fruit production, thus only by selecting female/pollen parent combination fruit set, size, appearance, development period and fruit quality can be can be altered as per consumers need. We still don't properly understand the xenia and metaxenia effect. Before planning an orchard, choosing the right pollinators could be a new topic of research for producing quality fruit. However, further research will be required to clarify the function and mode of action of the pollen sources for influencing fruit (metaxenia) and seed (xenia) attributes.
References:
1. Alizadeh-Salte, S., Farhadi N., Arzani K. and Khoshghalb, H. 2018. Almond oil quality as related to the type of pollen source in Iranian self-incompatible cultivars.
Int. J. Fruit Sci., 18:29–36.
2. De Jong, T.J. and Scott, R. J. 2007. Parental conflict does not necessarily lead to the evolution of imprinting. Trends Plant Sci., 12:439–443.
3. Denney, J.O. 1992. Xenia includes metaxenia. HortScience, 27:722–727.
4. Dunn, L.C. 1973. Xenia and the origin of genetics. Proc. Amer. Philos. Soc.
117:105–111.
63
5. Engel, M.L., A. Chaboud, C. Dumas and S.M. Cormick. 2003. Sperm cells of Zea mays have a complex complement of mRNAs. Plant J., 34:697–707.
6. Farag, K.M., Elsabagh, A.S. and ElAshry, H.A. 2012. Fruit characteristics of
"Zaghloul" date palm in relation to metaxenic influences of used pollinator.
American-Eurasian J. Agric. Environ. Sci., 12 (7): 842-855.
7. Focke, W.O. 1881. Die Pflanzen-Mischlinge:einBeitragzurBiologie der Gewachse.
Bomtrae-ger, 510-518, Berlin.
8. Gharaghani, A., GhasemiSoloklui, A. A., Oraguzie, N. And Zare, D. 2017. Pollen source influences fruit quality, aril properties, and seed characteristics in Pomegranate. Intl. J. Fruit Sci., 17: 333–348.
9. Golzari, M., Hassani, D., Rahemi, M. and Vahdati, K. 2016. Xenia and metaxenia in Persian walnut (Juglans regia L.). J. Nuts, 7:2, 101-108.
10. Herbert, S. W., Walton, D.A. and Wallace, H.M. 2019. Pollen-parent affects fruit, nut and kernel development of Macadamia. Sci.Hortic., 244:406–412.
11. Huang, R., Zhang, Y., Zhang, Q., Wang, Z., Xia, G., Huang, J. and Hu, Y. 2019.
Transcriptome analysis of photosynthetic capacity of exocarp of heterogenously pollinated Caryacathayensis. Front. Plant Sci.,55:128-137.
12. Kermicle, J.L. 1978. Imprinting of gene action on maize endosperm, p. 357–371.
In: Walden, D.B. (ed.). Maize breeding and genetics. Wiley, New York, NY.
13. Kim, M., Canio, W., Kessler, S. and Sinha, N. 2001. Developmental changes due to long-distance movement of a homebox fusion transcript in tomato. Science, 293:287–289.
14. Kudo, H. and Harada, T. 2007. A graft-transmissible RNA from tomato rootstock changes leaf morphology of potato scion. HortScience, 42: 225–226.
15. Liang, X., Chen, J., Yang, L., Zhao, Z. and Shi, Z. 2016. Effect of pollination combination from northern and southern Chinese chestnut on fruiting characteristics. North. Hort., 40:4–8.
16. Liu, Y. 2008. A novel mechanism for xenia. HortScience, 43(3): 706.
17. Liu, Y. S. 2006. Response to Till-Bottraud and Gaggiotti: Going back to Darwin’s works. Trends Plant Sci., 11:472–473.
18. Ma, B. L., Subedi, K. and Reid, L. M. 2004. Extent of Cross-fertilization in Maize by pollen from Neighbouring transgenic hybrids. Crop Sci., 44(4): 38-43.
19. Militaru, M. and Butac, M. 2015. Effect of Metaxenia on the Fruit Quality of Scab Resistant Apple Varieties. Agric. Agric. Sci.Procedia, 6: 151-156.
20. Mizrahi, Y., Mouyal,J.Nerd,A. and Sitrit,Y. 2004. Metaxenia in the vine cacti Hylocereus polyrhizus and Selenicereus spp. Ann. Bot., 93:469–472.
21. Omar, A., Al-Obeed, R., Soliman, S. and Al. Saif A.M.2014. Effect of pollen source and area distribution on yield and fruit quality of 'Khalas' date palm
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(Phoenix dactylifera L.) under Saudi Arabia conditions. Acta Adv. Agric. Sci., 2(3):
7-13.
22. Pozzi, F.I., Pratta,G.R.,Acuna,C.A. and Felitti, S.A. 2019. Xenia in bahiagrass:
Gene expression at initial seed formation. Seed Sci. Res., 29:29–37.
23. Sabir, A. 2015. Xenia and metaxenia in grapes: differences in berry and seed characteristics of maternal grape cv. 'Narince' (Vitis vinifera L.) as influenced by different pollen sources. 2015.Plant Biol.,17:567–73.
24. Sanchez-Perez, R.,Arrazola, G. Martin, M. L.,Grane, N. and Dicenta, F. 2012.
Influence of the pollinizer in the amygdalin content of almonds. Sci.
Hortic.,139:62–65.
25. Shafique, M., Khan, A., Malik, A., ShahiD, M. Rajwana, I., Saleem, B., Amin, M.
and Ahmad, I. 2011. Influence of pollen source and pollination frequency on fruit drop, yield and quality of date palm (Phoneix dactylifera L.) cv. Dhakki. Pak. J.
Bot., 43(2): 831-839.
26. Swingle, W.T. 1928. Metaxenia in the date palm- possibly a hormone action by the embryo or endosperm. J. Hered., 19(6), 257-268.
27. Wang, H., C. Wang, L. Cheng, Y. Chang, P., He and Li, L. 2017. Effect of metaxenia on volatile compounds in bagged apple fruit of Fuji. Agr. Sci. Technol., 18:583–610.
28. Westwood, M.N. 1989. Temperate-zone pomology. W.H. Freeman, 373-376, New York.
29. Yang, Q., Fu, Y., Liu, Y., Zhang, T., Peng, S. and Deng, J. 2020. Novel classification forms for xenia. HortScience, 55(7): 980-987.
30. Zhang, M.M., Wang,Z.H., Mao, Y.F.,Hu, Y.L. Yang, L.,Wang,L.L., Zhang, L. L.
and Shen, X. 2019. Effects of quince pollen pollination on fruit qualities and phenolic substance contents of apples. Sci.Hortic., 256:108628.
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