This chapter discusses plant breeding methods and technologies and their potential for increasing oat crop yields and oat crop improvement. It specifically introduces the importance of hybrid vigour and a non-stress environment for higher percentage heritability selection and therefore providing a more productive conventional plant breeding method for the improvement of crops. This chapter draws together the results from trials presented in Chapters Three and Four to show the superiority of the Isolection method over the conventional oat breeding method for development of high yielding, multi-purpose oat varieties. Genetic Modification (GM) technology and crops derived from cloning, a process devoid of hybrid vigour, are compared with proven plant breeding methods.

Introduction

In this chapter, GM technology and conventionally bred crops are briefly compared with proven plant breeding methods, with respect to hybrid vigour and the economic viability of both systems. These proven methods of plant breeding are also considered historically. These methods are (A) traditional landrace cropping, (B) conventional Mendelian breeding and (C) Isolection Mendelian breeding. There are important reasons for considering the limitations of comparing the yields of GM and conventionally bred crops and these are discussed in this chapter.

GM plant breeding technology

Overview

GM crops have one parent only, to which is transferred only one, or a limited number, of genes from an organism in another genus (hence the term “transgenic”). Currently this gene (or genes) gives the plant resistance to chemical spraying for control of either weeds or pests. Conventional crops, on the other hand, derive from crossing intraspecific varieties to unite a multitude of “matching genes” from two parents, conferring hybrid vigour. This hybrid vigour, in varying degrees, applies to all conventionally bred crops but not to GM crops. For example, close crossing within the ecospecies, like winter oat x winter oat, a feature of the Isolection system, gives more hybrid vigour to the progeny than wider crossing, like winter oats x spring oats. This fact was established at Glen Innes in NSW (see previous chapters). Furthermore, yield comparisons are invalid without specifying the environment and its interaction with the varieties being compared. There are proven agro-ecological factors of weed and pest control: crop rotation and length of fallow, specially suited for high-yielding conventional varieties, depending on regional soils and climates (Fettell, 1980).

Information on comparative crop trials of GM versus non-GM crops in Australia has been limited (Guerin and Guerin 2003). Studies are, however, emerging outside Australia comparing GM crops with conventionally bred crops, though few are scientifically designed for meaningful comparison of GM crops with those that are conventionally bred. For instance, a report by the British Soil Association, on GM crops in North America, found that with the exception of crops possessing Bacillus thuringiensis (Bt) for pest resistance, the GM crops yielded lower than conventional crops (Anonymous, 2002a). Despite higher yields with Bt corn, US farmers lost $US 1.31 per acre ($A6 per ha). The Soil Association reported widespread contamination of seed sources, crops and the human food chain, with GM crops costing the US economy $US12 billion over the previous two years.

Another report from the Canola Council of Canada seemed to favour GM crops (Anonymous, 2002b). The Council reports an average increase of $C14.33/ha in net returns to Canadian farmers growing transgenic canola, but 37% of Canadian farmers were staying with conventional lines because the cost, $C37/ha, of the Technology Use Agreement, was prohibitive. In addition, if a hybrid GM canola was being reported, it should have been compared with a hybrid non-GE canola, which would normally yield higher than its transgenic counterpart. In Arkansas, researchers found that transgenic soybeans yielded almost 10% lower than conventional soybeans (Lappé and Bailey, 1999).

Description of GM technology

Gene technology enables plants to be cloned from a single cell of the parent plant. Gene transfer technology then enables cloned genes for a desired trait to be blasted into cultured plant cells with a “gene gun” that forces the genes into the cell. The cells are cultured to form a tissue mass that will grow into a plant carrying the gene or genes for herbicide or pest resistance. This results in a source of inefficiency for breeding programs and high cost, in transferring the new gene into a commercially desirable conventional variety of the crop species being modified. Out of millions of plant cells that are bombarded with metal particles coated with DNA, only very few cells actually take up the DNA. If the tissue piece were then cultured, the untransformed or native cells of the invaded plant (selected to take the gene) would rapidly grow and swamp the few cells that had the added gene. Therefore, selectable marker genes are used to favour the growth of the cells that carry the new gene. A selectable marker gene is a gene that confers resistance to a substance that is toxic to normal plant cells. This marker gene is delivered to plant cells with the introduced gene and the cells are cultured in the presence of the toxic compound, as well as plant hormones to induce the cells to divide and grow. Only cells that contain the marker genes as well as the new gene (for pest or herbicide resistance) are able to inactivate the toxic compound, in order to survive and grow into complete plants. The selectable marker genes may be antibiotic resistance genes conferring resistance to antibiotics, or herbicide resistance genes that confer resistance to herbicide.

The importance of limiting gene transfers into wild populations

Outcrossing of GM with non-GM plants complicates the study of taxonomy and should be rigorously excluded from the Vavilovian⁶ centres of origin of specific crops and wild relatives. For example, GM mustard plants were found to be 20 times more likely to interbreed with related species than non-GM mustard plants (conventionally bred for the same herbicide resistance) (Burgelson et al. 1998). It has been reported that GM tomatoes have been grown without the consent or knowledge of Authorities in Guatemala, a Vavilovian centre, where hundreds if not thousands of indigenous tomato varieties are grown. It is also claimed that cross-pollination distances needed for strict isolation have been ignored, even for pharmaceutical crops, so long as potential dangers, in the 1995 joint consultation between WHO and FAO, were “judged to be unrelated to food safety” (Anderson, 2000).

Conventional crop plant breeding

This is independent of genetic modification and may be divided into three productive methods or systems developed over 8-10,000 years and according to the results of particular plant breeders: (A) Traditional, (B) Conventional Mendelian and (C) the Isolection Mendelian breeding systems. These mechanisms are natural, like the agents of wind, pollinating insects and honeybees, all of which are prevented from causing evolution by means of the genetic barriers between species and even ecospecies. Here, however, the breeder controls the hybridisations and selections. All three methods can benefit from the heritability of selections made in non-stress conditions (hand spacing of plants, not drill sowings) as has been achieved with oats in Australia (refer to Chapter Three).

Traditional landrace cropping

This is and has been a very successful period of maintaining peasant landraces of different species and ecospecies in the various so-called Vavilovian centres of origin of our cultivated crop plants. These are mixtures of homozygous plants most suitable for their particular soil and climatic conditions, e.g., small-seeded, rust-resistant varieties or eco-species in continental climates and large-seeded, early maturing types, in Mediterranean climates. These centres are also reservoirs of genes for high yield. Maize trials show that the degree of heterosis, when open-pollinated varieties are used in hybrid combinations, is considerably higher with varieties from Latin America (rich in Vavilovian centres) than with US Corn Belt varieties (Mangelsdorf, 1952).

There is ample evidence that our various crop species have had single and sudden origins. The great genetic variability present in isolated peasant farmers’ landraces suggests that they were created, not from single plants, but from a multitude of “first parents” to produce their multicultural (due to companion cropping) varieties with resistance to a broad spectrum of rusts, blight and climatic variability. The companion cropping of peasants often reduces disease and increases total yields.

Vavilov recorded the various large-seeded varieties of the Mediterranean centre of origin, relative to the continental centres. His critics put this down to the greater antiquity of Mediterranean agriculture but Vavilov found this to be no greater than that of Asia Minor, Afghanistan or China. Oat grazing trials at Glen Innes after 1957 vindicated Vavilov (see earlier chapters of this book). Farmers in the centres of origin should be encouraged to separately maintain their landrace varieties, free from introduced high yielding varieties, which soon succumb to rusts and blight. These unique centres are, or should be, universal reservoirs of germplasm in situ for all plant breeders, in preference to under-utilised gene banks (Harlan, 1992).

Inbreeders and outbreeders. Here we must distinguish out-breeders like maize from self-pollinated crops like wheat, oats and barley, peas and beans. The latter are designed to be resistant to inbreeding and respond well to pure-line breeding. There is enough natural crossing (4% in wheat, 0.5% in oats) to maintain their yields in the centres of origin.

Darwin was probably right in stating that selection, over thousands of years, had not made our crop plants higher yielding (Darwin, 1868). Not until the 20^th century did hybridisations and introductions from the centres of origin combine to give significant increases in crop yields, and this is shown in the following sections.

Conventional Mendelian plant breeding

During Gregor Mendel’s life (1822-84), hybridisations between different varieties, or ecotypes within the same species, formed the basis of the Mendelian laws of inheritance. G.H. Shull later showed that the depression in yield, following inbreeding of maize, was due to homozygosity. He hypothesised that hybrid vigour must be associated with the heterozygosity arising from crossing. In 1914, he proposed the term “heterosis” for this effect. His single-cross interline hybrids, however, yielded much lower than a standard maize variety on the same area. In 1917, D.F. Jones used double-cross interline hybrids to reduce the cost of seed sufficiently to justify hybrid seed production. This could increase maize crop yields by 25 to 35% and sometimes by 50%, as compared with the best selected open-pollinated varieties (Guzhov, 1989).

Natural selection. Regarding self-pollinated crops, it was assumed for half a century after Darwin that by selecting a certain type of plant for propagation, the species or variety would be continually transformed in the same direction. This was a result of acceptance of Darwin’s evolution theory and later of Galton’s “law” of inheritance, as applied to selection. Selection work commenced by W. Johannsen in 1901 on common garden bean, Phaseolus vulgaris nana var. Princess, refuted this theory in papers he wrote from 1903 to 1913 (Babcock and Clausen, 1918). Princess was actually a blend of highly homozygous pure lines. Johannsen found that selection within a pure line was without effect. Louis de Vilmorin’s wheat plants also remained identical in all respects after 50 years during which annual selection had been continued.

T.H. Morgan (1866-1945) also rejected the possibility of natural selection bringing about evolution and found that pleiotropy, the state in which one gene has effects on a number of different traits, could control several factors in Drosophila and even cause reduced fertility. This led to the hypothesis that genes occurred in linear order along the length of the chromosome. This concept could explain linkage, which enables a group of genes to be inherited together. This was a great help to conventional breeders. Conventional Mendelian breeding reached a high point with the Green Revolution, from 1950 to 1990, when world population doubled while food production quadrupled (referred to in Chapter One).

Isolection Mendelian plant breeding (Isolection Method)

The Isolection system of breeding (described in Chapter Three) was conceived and executed for the first time in Australia at the New England Agricultural Research Station, Glen Innes, in the drought year of 1957 (Guerin and Guerin, 1992). All the early generation oat plants were widely spaced, at 3.66-5.38 plants/m², in contrast to 13.99-21.53 plants/m² in the Temora Research Station drill-sown breeding plots. The object of this wide spacing was to eliminate environmental variance (due to competition and stress between plants) and to make more effective prostrate genotype selections.

This method of breeding of oats (described in Chapter Three) has lead to the development of varieties of oats that are significantly higher yielding than traditionally or conventionally bred varieties.

As an example, one trial at Richmond (Table 6.1) demonstrated the differences in yield of oat varieties bred by conventional and the new Isolection method clearly as all High-vigour (isolection-bred) varieties and lines (5 in total) reported higher pasture cut, hay and total yields than any of the conventionally bred varieties and lines.

Another example of this higher yielding attribute of the Isolection-bred variety, specifically Blackbutt, was also demonstrated in a trial at Gunning in 1999 where it was tested with the conventionally-bred variety, Nile (Table 6.2), as found by Powell (2000), who showed Nile and Eurabbie to be inferior to Blackbutt in recovery. Nile is a cross between Blythe (winter type) x Avon (frost susceptible type) and was significantly inferior to Blackbutt in grain yield after 2 grazings. Numerous trials were conducted in Australia, particualry NSW, comparing the yield attributes of Isolection-bred and conventionally-bred oat cultivars and these have been presented in Chapters Three and Four of this book, over the 29 year period from 1961 to 1990.

Table 6.3 draws together 12 of these trials, all of which provided statistically analysed results and that were conducted independently by researchers and agronomists other than the Author. This table presents the data previously reported in earlier chapters as yield ratios of Isolection-bred to the conventionally-bred oat variety (Cooba). Cooba was selected as a check variety for grazing and grain because it has been available to Australian farmers prior to the breeding of the Isolection-bred lines and varieties. In 83% of these trials, isolection-bred varieties reported higher yields than Cooba for pasture cut yields. In all (100%) of these trials, the grain recovery after grazing, grain only and total biomass yields were higher for Isolection-bred varieties than Cooba. In one trial, the Isolection-bred variety Blackbutt, reported three times the pasture cut yield of Cooba. In another trial, the Isolection-bred variety, Carbeen, yielded more than twice that of Cooba for grain recovery after grazing. In summary, the ratios of Isolection bred varieties to conventionally-bred varieties were for: pasture cut yield was 1.1:1, for grain recovery after grazing was 1.7:1; for grain only yield (i.e no grazing) was 1.5:1; and for total biomass yield (pasture cuts and grain after grazing) was 1.4:1. These ratios clearly demonstrate the superiority of the Isolection varieties and lines for total yield over the standard or check variety, Cooba, which is a conventionally-bred cultivar. In particular, the data in Table 6.3 highlights the stand out performance of Isolection-bred varieties and lines for producing grain yields after grazing.

Features of the Isolection breeding method. The features of this breeding method are: (A) A high rate of success in crossing oats before starting, in order to produce a large number of homozygous F₂ plants; (B) The two parents to be phenotypically similar (as in a narrow cross) but genotypically different; (C) The F₂ generation plants to be widely spaced by hand, hence the name of Isolection system, to “isolate” pure breeding lines; (D) Linkage assists the rapid breeding method, by telling us that a winter cereal has morphological features like prostrate habit of growth and deep root system, correlated with resistance to frost, drought and grazing damage.

Wild gene transfers are not necessary. Regarding the close crossing aspect of the Isolection breeding system, there is no lack of genetic engineering techniques to transfer genes from wild species to new cultivars but even within the limits of complete fertility and genetic exchange, there are severe restrictions on quantitative gene transfer (Röbbelen 1978). Röbbelen points out that even European potato breeding, based on only 5 introductions and with only 10 alleles for a given trait, can produce millions of genotypes. Wild oat species found in Spain and Asia Minor are very rare on deep fertile soils and seem to have few economic virtues (Rajhathy and Thomas 1974). With sound crop rotations and good farm management, there is no need for wild gene transfers. Even diploids (2n = 14) like Pilosa, Ventricosa, Prostrata, Damascena and Longiglumis cannot be crossed together.

Comparing GM with conventional crops

This section highlights the differences between the 2 main systems of breeding, with respect to breeding mechanism, benefits, costs, risks and agro-ecological factors, which are summarised in Table 6.3. Yield comparisons between GM and conventional crops, which were recently investigated in a survey of available data, showed that there have been no readily available yield per se comparisons (Guerin and Guerin, 2003). There was no clear evidence that biometrically designed or analysed trials had been carried out or published in the United States. Similarly no such trials of GM cotton versus conventional cotton had been carried out openly at the Narrabri cotton station in NSW, Australia, before GM cotton (the only GM crop grown in Australia) was released to cotton growers. This was the first time that NSW Agriculture had failed to provide Australian growers with an independent yield analysis before allowing a completely alien type of variety to be grown⁷.

There are some key comparisons between GM and conventional breeding. Firstly, conventional breeding is a natural technology and is more rapid than GM crop development. A greater length of time is required to backcross to elite conventional lines, make selections and build up seed supplies of new GM varieties for yield testing in comparison with conventional varieties. There are no yield comparisons in Australia of crops bred by conventional versus GM technology with the consequence that GM cotton has been released to farmers without any yield information. Breeders of conventional crops, on the other hand, can release a new variety every two or three years but are obliged to furnish State Departments of Agriculture with several years of biometrically analysed yield data.⁸

Secondly, only a limited number of genes and no hybrid vigour are added by the GM process. This makes GM technology unsuitable for the multigenic requirements of winter cereal breeding for high grazing and grain yields. In conventional or Isolection (Mendelian) plant breeding, one looks for traits, not genes: a big advantage over GM crop production, which adds only one or a few genes.

Thirdly, GM crops have the advantage that they can be sprayed to kill weeds that emerge with the crop but the early competition involved will reduce crop yield. The no-till fallow of GM crops does, however, have other disadvantages (A) rodent, insect and disease incidence increase due to surface residues and (B) soil temperature may decrease by as much as 6°C at a depth of 2.5 cm in spring, giving poor germination (Anonymous, 1982). Fourthly, to gain full benefits from conventional cropping, farmers must plan for weed-free sowing conditions. Fallowing cultivations are essential for Central and Northern NSW and for Queensland, although no-till fallowing by herbicide spraying can replace some fallow cultivation (Percival, 1979).

Finally, the cost of GM seed is high relative to conventionally bred varieties because of the seed patenting process.

Table 6.1 Isolection-bred versus conventionally-bred oat varieties (Richmond, NSW)^a.

Breeding Method	Cultivar	Cultivar Origin	Yield (T/ha)				Frost Scoree
			5Pb	Hayc	July Pd	Total
Isolection	P4315	High-vigour cross, Glen Innes	6.55	3.62	1.45	10.17	1
	P4314	High-vigour cross, Glenn Innes	6.21	3.70	1.23	9.91	1-
	Blackbutt	High vigour cross, Glen Innes	6.67	2.86	1.35	9.53	1
	871-1G59	High-vigour cross, Glen Innes	5.66	2.97	0.83	8.64	2
	871G59	High-vigour cross, Glen Innes	5.60	2.99	0.74	8.59	2
Conventional	Klein69B	Argentina	5.01	3.37	0.72	8.38	2+
	Cooba	Temora	5.18	2.21	0.95	7.39	3+
	Fulghum	USA	4.87	2.20	0.64	7.07	3
	F x Vic	Temora	4.21	2.47	0.52	6.68	4+
	Coolabah	Temora	4.09	2.08	0.45	6.17	6+
	FxAvon 21	Temora	3.89	2.23	0.36	6.12	4+
	Avon x Fk	Temora	3.96	1.93	0.28	5.90	7+
	Avon x O	Temora	4.04	1.81	0.33	5.85	8
	FxAvon 20	Temora	3.45	2.11	0.23	5.57	7
	Fulmark	Temora	3.78	1.70	0.20	5.48	9
	M1305	Temora	3.36	1.48	0.25	4.85	7
	Algerian	Algeria	3.38	0.60	0.19	3.98	8
	SDf	-	0.90	0.99	0.34	1.54	-

^a This trial was conducted at Hawkesbury Agricultural College, Richmond, NSW in 1966; ^b5P = 5 Pasture cuts in dry matter yield per hectare; ^c Hay = hay recovered after 5P; ^d July P = Pasture yield during coldest month; ^e Frost scored 0 for no damage and 10 for extreme damage, during a cold, dry winter (rainfall only 50% of the 86-year mean). Date of Sowing: 25^th March; ^f SD = significant difference, obtained by biometrical analysis performed by NSW Agriculture Biometricians at Rydalmere, NSW, Australia, during 1966-1967.

Table 6.2 Isolection-bred versus conventionally-bred oat varieties (Southern Highlands NSW)^a.

Breeding method	Cultivar	Origin (oats)	P cut 1 (t/ha)	P cut 2 (t/ha)	Grain recovery (t/ha)
Isolection	Blackbutt	Glen Innes	3.49	1.46	3.70
Conventional	Nile	Tasmania	4.00	1.33	3.10
	Eurabbie	Temora	4.17	1.37	1.80
	SDb		0.65	0.26	0.50
	CV (%)c		10.72	12.6	14.5

^a From Powell (2000). The above trial was sown on 1^st April, 1999 and was harvested on 22^nd December; ^b = significant difference; ^c = coefficient of variation. Grazing date for P cut 1, was 11 June 1999 and for P cut 2, 20 August 1999.

Table 6.3 Yield ratios of Isolection-bred to conventionally-bred oat variety (Cooba) across climatic zones from statistically analysed trials over a 29 year period^a.

Trial location	Year	High-vigour Line Yield /Cooba Ratios				Climatic Zone
		Pasture Cuts	Grain Recovery	Grain Only	Total Biomass
Tamworth	1961	1.2	1.9	-	1.3	Summer rainfall
Glen Innes	1962	1.1	2.9	-	1.3	Summer rainfall
Glen Innes	1962	1.2	1.6	-	1.2	Summer rainfall
Richmond	1966	1.3	-	-	1.4	Uniform/Summer rainfall
Cowra	1966	1.0	1.5	-	1.3	Uniform rainfall
Galong	1968-72	1.0	1.7	-	-	Uniform rainfall
Niangula	1969	1.3	-	-	-	Summer rainfall
Redderstone	1969	1.0	1.3	-	-	Summer rainfall
Parkes	1969	1.5	1.4	-	-	Uniform rainfall
Tamworth	1973	0.9	1.9	-	1.9	Summer rainfall
South Australia	1980	1.1	2.2	-	1.5	Winter rainfall
Colleambally	1985	-	-	1.5	-	Winter rainfall
Adelong	1985	-	1.2	-	-	Winter rainfall
Blayney	1990	0.9	1.5	-	1.2	Uniform rainfall
Average	1961-1990	1.1	1.7	1.5	1.4	All zones

^a The ratios in this table are derived from the data tables presented in Chapters Three and Four and from Guerin (2003).

Conventional plant breeding in Australia has been conducted hand-in-hand with crop rotations, judicious fallowing (cultivation of moist soil, or sheep grazing if the soil is dry). Contour tillage and contour banks can prevent erosion and store extra moisture. Sheep grazing prevents weed seeds from setting and increases soil organic matter. Both in Australia and America, judicious fallowing, has been recommended for the past 50 years (Guerin, 1961). Thus, a 9-month fallow can give a 100% yield increase over a 3-month fallow (Fettell, 1980).

Fisher (2006) considers that GM crops are unlikely to deliver practical results in terms of yield potential increase for a long time, and any increases from the technology are entirely conditional on much more investment in plant research, plant and crop physiology, conventional breeding and genetics.

Important challenges from gm crop technology

There are potential unintended consequences from GM technology. For instance, gene technologists claim that they are only controlling evolution. In fact they merely show that genetically modified organisms have a very low survival rate and that evolution, if it ever happened, was not by this process. This, however, should not be used as an argument for releasing genetically modified organisms. Cross-pollination can take place, giving rise to undesirable or weedy plants, animals or fishes, lacking in health and true hybrid vigour, or euheterosis.⁹ Genetic modification reduces euheterosis and depends upon backcrossing to elite, high yielding conventional varieties, before release.

Growing GM crops also presents a risk of contaminating conventional crops. This has resulted in litigation and the loss of premium markets in the UK, Europe, Japan, China and other countries. GM crops have to contend with consumer resistance. This is based on evidence that long-term nutritional concerns are not being monitored. There is also a strong ethical component, upholding the genetic integrity of the species. This point need not, however, lower the value of gene technology, excluded from the natural environment, for fundamental research, as in glasshouses.

In relation to oats, the health benefits from this grain are due to its unique properties. The β-gluten in rolled oats and especially in oat bran is unique in the treatment of cholesterol, blood pressure, heart disease and diabetes. The oat lipids are rich in antioxidants considered to be important in the treatment of cancer. The superior biological value of oats relative to other grains makes it closer in make-up to a legume. These attributes have been discussed in detail in Chapter One. It is imperative, therefore, that oats be preserved from transgenic transfers.

Engineered traits in plants to date are limited to a few characteristics. The engineered plants must then be back-crossed into a conventional variety. This chapter stresses the importance of multigenic traits for high yields by close crossing within the species.

Table 6.4 Comparing features of GM crops with conventional crops^a.

Feature	GM Crops	Conventional Crops
Type of breeding	Cloning and backcrossing to an elite conventionally bred variety	Independent of GM: a male x female cross.
Years to breed a variety	8-10 years	Every 2-3 years
Number of genes added	Usually one or two genes	Possibly 50,000 allelic pairs of genes involved
Source of yield benefits	Controlling weeds/pests	Hybrid vigour
Land preparation	All tillage is replaced by herbicide spraying	Some tillage is needed to kill all weeds and residues
Weed infestation risk	Weeds compete early with crop and reduce yield	More emphasis on fallow tillage increases yield
Cost to farmer	High cost of patented seed	Relatively low cost seed
Consumer acceptance	High resistance	Universally accepted

^a From Guerin and Guerin (2003).

Conclusions

The non-stress environment of the Isolection Mendelian system resulted in the breeding of superior dual-purpose oats, relative to the conventional Mendelian system, as well as in a more effective detection of heritability. This was shown up by a more rigorous assessment of resistance to grazing, frost and drought. Grain quality was also improved. A comparison of GM crops and conventionally bred crops show that GM crops lack versatility and economic advantage. This is because GM crops are, at present, designed for weed and pest control, not for agro-ecological factors, like crop rotation and contour tillage. The necessity for breeders to have to back-cross their GM varieties with elite conventional varieties effectively slows the process of releasing new varieties. Finally, the unintended consequences of releasing GM crops, particularly in the Vavilovian centres of landrace varieties, for maintenance of valuable germplasm such as oats, should not be underestimated.

References

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⁶ Geographical centres of origin that possess plant varieties with unique genotypes and naturally occurring biodiversity, and are usually isolated by geographical barriers.

⁷ The Author requested this information from the Director-General and officers concerned on a number of occasions, before the release of GM cotton, but never received any replies.

⁸ The Author released 3 new oat varieties: Bundy in 1965, Mugga in 1966 and Blackbutt in 1974, as a result of 7 years of oat plant breeding from 1957 to 1964.

⁹ Euheterosis is hybrid vigour for sexual reproduction and seed yield. It is intra-specific.