Breeding of Hybridization
Hybridization is a method by which an offspring is produced through the crossing of two different plant varieties of the same species. In other words, it refers to the development of plants by combining inherited qualities of one plant with that of another through the fertilization of female with male gametes.
TYPES OF BREEDING
(i)
In-breeding
: This is the pollination and fertilization of closely related crop plants in order to retain certain desirable characteristics. This can lead to pure breed or pure line.
(ii)
Pure line
: A plant which has been self-fertilized or crossed continuously with closely related species (inbred) for many generations, so that the desirable qualities it possesses do not change from generation to generation, is called a pure line. Pure line will always reproduce itself with great precision.
(iii)
Cross breeding
: This is the pollination and fertilization of unrelated crop plants belonging to different breeds. This results in the production of an offspring which is superior to the average performance of the parents. This is called hybrid vigour “heterosis”.
ADVANTAGES OF BREEDING
(i) breeding can produce a superior offspring resulting in hybrid vigour or heterosis (cross breeding)
(ii) Progency grows more rapidly (cross breeding)
(iii) Production of pure line (in-breeding).
(iv) Offspring can withstand variations of environment (cross breeding)
DISADVANTAGES OF BREEDING
(i) breeding could lead to “inbreeding depression”, which is the depression or loss in vigour and performance of offspring (in-breeding)
(ii) There is a drop in production or yield of crops in terms of quantity and quality (in-breeding)
(iii) breeding may lead to poor or low resistance to disease attack (in-breeding)
Productivity of crops can be achieved through a combination of methods which include
:
(1) Crop Improvement Methods: As discussed earlier, crops can be improved through introduction, selection and hybridization.
(ii) Proper Timing of Planting: Crops should be grown at the right time to avoid high temperature, inadequate rainfall or abundance of pests and diseases during growth.
(iii) Adoption of Better Cultivation Methods: The adoption of better methods of cultivation like crop rotation which adds nutrients to soil, prevents erosion, pests and diseases outbreak and helps to increase yield.
(iv) Use of Manures and Fertilizers: The use of manure like farm yard compost and green manure in combination with the use of fertilizers helps to add nutrients to soil and promotes good growth of crops.
(v) Control of Pests of Crops: The control of pests of crops which I cause reduction in yield and growth can help in the improvement of crops.
(vi) Control of Diseases of Crops: Diseases also cause a reduction in growth and productivity of crops. Where they are adequately prevented, it will lead to improvement of such crops.
(vii) Use of Resistant Varieties: Some varieties of crops are capable of resisting disease’s attack and can mature early thereby increasing the yield of crops.
(viii) Use of good crop varieties: There are some varieties of crops which naturally will grow well in different environmental conditions. Such crops do help to increase the overall production of such crops
HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.
1. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
2. DISEASES
3. 52. SOIL MICRO-ORGANISMS
4. ORGANIC MANURING
5. FARM YARD MANURE
6. HUMUS
7. COMPOST
8. CROP ROTATION
9. GRAZING AND OVER GRAZING
10. IRRIGATION AND DRAINAGE
11. IRRIGATION SYSTEMS
12. ORGANIC MANURING
13. FARM YARD MANURE
14. HUMUS
15. COMPOST
16. CROP ROTATION
17. GRAZING AND OVER GRAZING
18. IRRIGATION AND DRAINAGE
19. IRRIGATION SYSTEMS
20. INCUBATORS
21. MILKING MACHINE
22. SIMPLE FARM TOOLS
23. AGRICULTURAL MECHANIZATION
24. THE CONCEPT OF MECHANIZATION
25. PROBLEMS OF MECHANIZATION
26. SURVEYING AND PLANNING OF FARMSTEAD
27. IMPORTANCE OF FARM SURVEY
28. SURVEY EQUIPMENT
29. PRINCIPLES OF FARM OUTLAY
30. SUMMARY OF FARM SURVEYING
31. CROP HUSBANDRY PRACTICES
32. PESTS AND DISEASE OF MAIZE- ZEA MAYS
33. CULTIVATION OF MAIZE CROP
34. OIL PALM
35. USES OF PALM OIL
36. MAINTENANCE OF PALM PLANTATION
37. COCOA
38.
39. PROCESSES IN COCOA CULTIVATION
HOLING AND LINING
40. YAM
41. LAND PREPARATION FOR YAM
42. DEPT OF PLANTING
43. SPACING OF YAM
44. PLANTING DEPT OF YAM
45. STORAGE OF YAM
46. STAKING OF YAM
47. HARVESTING OF YAM
48. COWPEA
JUTE
49. FORAGE CROP AND PASTURE
50. FORAGE GRASSES
51. SILAGE
52. PASTURE
53. TYPES OF PASTURE
COMMON GRASSES AND LEGUMES
54. GRASSES
55. LEGUMES
56. ESTABLISHMENT OF PASTURES
57. 201. FORAGE PRESERVATION
58. HAY SILAGE
59. FORESTRY IMPORTANCE OF FORESTRY 206. FOREST MANAGEMENT FOREST REGULATION DEFORESTATION AFFORESTATION
60. DISEASES AND PESTS OF CROPS
61. MAIZE SMUT
62. RICE BLAST
63. MAIZE RUST
64. LEAF SPOT OF GROUNDNUT
65. COW-PEA MOSAIC
66. COCOA BLACK POD DISEASE
67.
68. CASSAVA BACTERIA BLIGHT
69. BLACK ARM BACTERIA BLIGHT OF COTTON
70. TOMATO ROOT KNOT
71. DAMPING-OFF OF TOMATO
72. ONION DOWNY MILDEW
73. STORED PRODUCE MOULD
74. PESTS OF CROPS
75. STEM BORERS
76. ARMY WORM
77. COCOA MIRIDS(CAPSIDS)
78. APHIDS
79. WHITE FLY SEED BUGS
80. CASSAVA CULTIVATION
81. CASSAVA MEALYBUGS
82. VARIEGATED GRASSHOPPER
83. GREEN SPIDER MITE
84. COTTON STAINER
85. COTTON
86. PESTS OF VEGETABLES
87. GRASSHOPPER
88. THRIPS
89. LEAF ROLLER
90. BEAN BEETLE
91. RICE WEEVILS
92. . PROBLEMS WITH PESTS CONTROL
93. CROP IMPROVEMENT
94. PROCESS OF CROP IMPROVEMENT METHODS OF CROP IMPROVEMENT
95. HYBRIDIZATION OF CROPS
96. ANIMAL PRODUCTION
97. THE DIGESTIVE SYSTEM OF ANIMALS
98. THE LARGE AND SMALL INTESTINE
99. RUMINANT ANIMALS
100. THE NERVOUS SYSTEM
101. THE NEURONS
102. A SYNAPSE ACTION IMPULSE REFLEX ACTION VOLUNTARY ACTION
103. THE CENTRAL NERVOUS SYSTEM
104. PERIPHERAL NERVOUS SYSTEM
105. THE REPRODUCTIVE SYSTEM MALE AND FEMALE REPRODUCTIVE SYSTEM
106. REPRODUCTIVE SYSTEM OF BIRDS
107. THE CIRCULATORY SYSTEM
108. THE PULMONARY CIRCULATION
109. THE HEART
110. THE RESPIRATORY SYSTEM
111. THE TRACHEA INSPIRATION THE EXPIRATION THE DIAPHRAGM
112. HEAT PERIODS OESTROUS CYCLE
113. MATING
114. PARTURITION
115. MAMMARY GLAND
116. LACTATION
117. EGG FORMATION IN POULTRY
118. LIVESTOCK MANAGEMENT
119. MANAGEMENT OF GOATS
120. REPRODUCTION IN GOAT
121. POULTRY
122. POULTRY MANAGEMENT
123. BATTERY CAGE SYSTEM
124. INTENSIVE SYSTEM
125. . SEMI-INTENSIVE EXTENSIVE SYSTEM
PROODING AND REARING IN POULTRY
126. POULTRY SANITATION
127. ANIMAL NUTRITION
128. RATION
129. CONCENTRATE
130. ROUGHAGE
131. NUTRIENT SOURCES AND FUNCTIONS
132. CARBOHYDRATES
133. PROTEIN FATS
134. MINERALS
135. VITAMINS
136. FEEDING MECHANISMS IN HOLOZOIC ORGANISMS
137. TYPES OF DIETS
138. FATTENING OR FINISHING DIETS
139. LAYER DIETS
140. BALANCED DIETS
141. LACTATION DIETS
142. MALNUTRITION
143. DISEASE, CAUSES, SYMPTOM CORRECTION
144. RANGE MANAGEMENT AND IMPROVEMENT
145. LIVESTOCK DISEASES
146. VIRAL DISEASES
147. RINDER PESTS
148. NEWCASTLE DISEASE
149. BACTERIA DISEASES
150. ANTHRAX
151. BRUCELLOSIS
152. TUBERCULOSIS
153. FUNGAL DISEASES
154. PROTOZOAN DISEASES
155. TRYPONOSOMIASIS
156. COCCIDIOSIS
157. RED WATER FEVER(PIROPLASMOSIS)
158. ENDO PARASITES
159. TAPE WORM
160. ROUND WORM OF PIGS
161. LIVER FLUKE
162. ECTO PARASITES
163. TICK
164. LICE
