000			02127nab a22002897a 4500
999			_c61651 _d61643
001			61651
003			MX-TxCIM
005			20240919021228.0
008			200410s1963||||ne |||p|op||||00||0|eng|d
022			_a0014-2336
022			_a1573-5060 (Online)
024	8		_ahttps://doi.org/10.1007/BF00033587
040			_aMX-TxCIM
041			_aeng
100	1		_aHermsen, J.G.T. _912220
245	1	0	_aHybrid necrosis as a problem for the wheat breeder
260			_aDordrecht (Netherlands) : _bSpringer, _c1963.
500			_aPeer review
520			_aHybrid necrosis is the premature gradual death of leaves and leaf sheaths in certain wheat hybrids. It is based on two complementary genes Ne 1 and Ne 2. Hitherto 89 Ne 1-carriers and 207 Ne 2-carriers from many countries are known (table 1 and 2). This corresponds with more than 18,000 different necrotic cross combinations. The degree of necrosis in the F1's varies greatly, due to multiple allelism of Ne 1 and Ne 2. Nine necrosis grades are described in table 3. Grades 6–8 are called severe necrosis (no seed is produced), 3–6 moderate necrosis (premature seed), 0–3 weak necrosis (normal seed). Most severely necrotic F1's could be brought to seed production by raising them under extra favourable conditions in a small growth-chamber. Growing moderately necrotic F1's in pots outside, at a high fertility level of the soil, resulted in a striking increase of the seed production. On the basis of the above mentioned data and results some practical advice is given to the breeders about the handling of necrotic crosses. In addition some ways to preclude hybrid necrosis are indicated, though the wheat breeder is advised against a systematic avoiding of necrosis because many combinations of excellent varieties then remain untried.
546			_aText in English
650		7	_aWheat _gAGROVOC _2 _91310
650		7	_2AGROVOC _91151 _aHybrids
650		7	_2AGROVOC _91187 _aNecrosis
650		7	_aPlant breeding _gAGROVOC _2 _91203
773	0		_tEuphytica _gv. 12, no. 1, p. 1-16 _dDordrecht (Netherlands) : Springer, 1963. _x0014-2336 _wu444298
942			_cJA _n0 _2ddc