INDEX 



543 



under asexual propagation, 320 

 biochemical models in Neurospora, 199- 



217 

 breeding for in cross-pollinated plants, 



55,400-417 

 breeding methods, 52-61, 400 417 



breeding for in self -pollinated plants, 55 



breeding for in vegetative ly propagated 

 plants, 56 



and chromosomes, 492 



in component traits, 303, 492 



and cytoplasm, 492 



development of concept, 49-65 



dispersed, 127 



and dominance, 224-35, 307, 494-516 



and Drosophila, 111, 475 



and early growth, 105 



environment-genotype interaction in, 

 488-91 



evaluation of, 329 



example of utilization, 66 



experiments with, 154-57 



as explained genetically, 173 



expression of, 224-25 



first use of term, 50 



gene interaction in, 320-29 



genetic basis, 100, 101 



genetic concepts, 61-65 



and genetic mechanisms, 100-103 



in heterocaryons, 202 



due to heterozj-gosity at one locus, 203- 

 15 



heterozygosity concept, 101 



importance of internal factors, 123 



inbreeding effects as related to defective 

 genes, 481 



and interracial and intra specific hybridi- 

 zation, 198 



and later growth, 106 



and linkage, 224-35, 285 



in maize, 1, 53 



in maize variety hybrids, 182 



in maize X teosinte, 183-84 



measures of, 479-81 



Mexican corns, 418-50 



in native open-pollinated varieties, 419- 

 25 



natural mechanisms for maintaining ad- 

 vantages of, 46-47 



nature and origin, 218-23 



in a new population, 418-49 



as observed in pre-Mendelian research, 

 1-14 



physiological basis of, 111-13 



physiological mechanism of, 112 



plasmagenes and chromogenes in, 224-35 



in polj-genic characters, 159 



in population genetics, 149-60 



potential, 140 



potential maximum, 340 



practical use of, 44 



as related to embryo and seed size, 103-4 



as related to heterozygosity, 103 



resulting from degenerative changes, 102 



reversed or negative, 225 



and rotational crossbreeding, 371-77 



scientific basis of, 1-2 



in self-pollinated plants, 52 



single locus, 102 



stimulus of heterozygosis, 49 



in sugar cane, 322 



in tomato root cultures, 109 



as tool of the animal breeder, 151 



usage, 98 



use of in 



farm crops, 51 



horticultural crops, 51 



silkworms, 51 



livestock, 51 



vegetative ly propagated plants, 51 

 utilization, 50-51, 55, 56 



Heterosis concept, 16, 17, 18 

 beginnings of, 14-48 

 defined, 48 

 in work with hybrid corn, 14 



Heterosis development 



as affected by nutritional factors, 111 

 as affected by water absorption factors, 

 HI 



Heterosis and dominance, as expression of 

 same physiological genetic phenomena, 

 307, 309 



Heterosis and gene recombination, 298-319 



Heterosis, maximum, 326-37 



with the dominance hypothesis, 287-91 

 methods of selection for, 350-51 



Heterosis and morphology, 141-46 



Heterosis in Neurospora, biochemical mod- 

 els of, 203 



Heterosis principle, 20 



Heterosis reserves, 140-41 



Heterosis, single gene, 155 



Heterosis tests, inbred lines, 330-51 



Heterosis theories 



genetic explanation, 62 

 interallelic action, 62 



Heterotic locus, 328 



Heterotic hybrid, determination of growth, 

 123 



Heterotic hybrids, 119 



Heterotic h3'brids and inbreds, structural 

 differences, 112 



Heterotic tomato hybrid, 123 



Heterotic vigor in excised tomato roots, 122 



Heterozygosis, 49, 152, 454 

 stimulus of, 224, 229, 282 



Heterozygosity, 100, 102, 332, 373 

 degree of, 350 



enforced in maize, 180-81, 193-96 

 range in degree of, 342 

 related to heterosis, 103 

 single locus, 199 



