Kombinacijska sposobnost i nasljeđivanje otpornosti nekih linija Zea mays L. protiv Colletotrichum graminicola (Ces) G. W. Wils. : doktorska disertacija - Brekalo, Josip, agronom; Martinić-Jerčić, Zdravko; Cvjetković, Bogdan; Parlov, Dragomir (Zagreb : J. Brekalo, 1995)
Sažetak: Umjetnom zarazom testirano je 1625 linija kukuruza domaćeg i stranog podrijetla na otpornost protiv antraknoze lista i stabljike i izdvojeno je osam izrazito otpornih linija. To su linije Bc 9, Bc 10, Bc 19064, Sp 288, H 99, Mo 17 kod kojih je otpornost već opisana u literaturi, a otkrivene su i dvije nove linije Zp 3 i Zp 4. Ovih osam linija (L) testirano je na otpornost protiv antraknoze lista i stabljike u križancima s devet elitnih, komercijalnih linija kao testera (T) i to: Bc 14, Bc 252, Bc 2923, A 632, A 619 Ht, B 84, B 73, C 123 i F 2. Analiza varijance i F test pokazali su u obje godine ispitivanja opravdane razlike u svim pokazateljima otpornosti protiv antraknoze lista i stabljike za linije, testere i križance (LxT),osim interakcije (LxT) kod postotka polomljenih biljaka.
Linije H 99 i Mo 17 pokazale su najslabiju otpornost protiv antraknoze lista i stabljike, a najotpornije su se pokazale linije Bc 19064, Sp 288, Zp 3 i Zp 4 u jednom ili više pokazatelja. Utvrđeni su opravdani efekti OKS i SKS, kako za otpornost, tako i za osjetljivost, ali su te vrijednosti kod većeg broja kombinacija različite u različitim godinama ispitivanja. Ispitani su različiti načini procjene otpornosti protiv antraknoze stabljike i to: ukupan broj zaraženih internodija, broj internodija s preko 75% zaraženog tkiva, vanjska obojenost (1-9), te postotak trulih i polomljenih biljaka. Korelacijske veze između različitih načina procjene otpornosti protiv antraknoze stabljike ukazuju da je vanjska obojenost najbolji pokazatelj otpornosti jer je u najjačoj vezi sa truleži stabljike, a najlakše je primjenjiva u praktičnoj selekciji.
Proučavana je shema nasljeđivanja otpornosti protiv antraknoze lista i stabljike kod izrazito otpornih linija Bc 10 i Zp 4 kroz populacije potomstva (P-1,P-2,F-1,F-2,BC-1,BC-2, a djelomično i BC-1S i BC-2S) dobivene križanjem s nekoliko osjetljivih linija različitog podrijetla. Analizom kvalitativnih svojstava nedvojbeno je potvrđena monohibridna shema nasljeđivanja otpornosti protiv antraknoze lista kod linija Bc 10 i Zp 4 u križanjima s osjetljivom linijom Bc 14. Međutim, to nije potvrđeno u križancima s drugim osjetljivim linijama (Bc 2923, Bc 252 i C 123), što znači da dominantni učinak alela otpornosti zavisi o kombinaciji križanja. Kod proučavanja otpornosti protiv antraknoze stabljike kao kvantitativnog svojstva korištene su populacije potomstva iz istih križanaca kao i za list.
Najveći dio u ukupnoj fenotipskoj varijanci činila je okolinska varijanca, pa je heritabilnost u širem smislu bila u većini križanja vrlo mala, a samo u nekim slučajevima osrednja. Heritabilnost u užem smislu, osim što je bila vrlo mala, u velikom broju križanja bila je čak s negativnim predznakom, a u jednom križanju veća od heritabilnosti u širem smislu, što je posljedica negativnih dijelova genotipskih varijanci.
Summary: Artificial infection was used for testing 1625 domestic and foreign maize inbreds for resistance to leaf and stalk anthracnose.Eight remarkably resistant lines were selected:Bc9,Bc10,Bc19064,Sp288,H99,Mo17 which have already been refered in literature for their resistance. Two new inbreds, Zp3 and Zp4 were detected. These eight lines (L) were tested for resistance to leaf and stalk anthracnose in crosses with nine elite, commercial lines as testers (T), namely Bc14,Bc252,Bc2923,A632,A619Ht,B73,B84,C123 and F2. In both years of testing, the analysis of variance and F-test showed significant difference in all indices of resistance to leaf and stalk anthracnose for lines (L), testers (T) and crosses (LxT), except the (LxT) interaction for stalk breakage. The lines H99 and Mo17 displayed the poorest resistance to leaf and stalk anthracnose.
The most resistant lines were Bc19064, Sp288, Zp3 and Zp4 in one or more indices. Significant GCA and SCA effects were found both for resistance and susceptibility, however, these values vary in different years for most combinations. Ratings of stalk antracnose by the different methods were studied, namely total number of internodes, intenodes with more than 75% of infected tissue, outer discoloration (1-9) and percent of rotted and broken plants. Correlative associations among the different rating methods of resistance to stalk anthracnose indicated that outer discoloration is the best indication of resistance because it correlates most closely with stalk rot and is easy for application in partial selection.
The pattern of inheritance of resistance to leaf and stalk anthracnose was studied for remarkably resistant lines Bc10 and Zp4 through populations of progenies (P-1,P-2,F-1,F-2,BC-1,BC-2,partly BC-1S and BC-2S) developed by crossing with several susceptible inbreds of different origin. The analysis of qualitative traits undoubtedly confirms monogenic pattern of inheritance of resistance to leaf and stalk anthracnose in the lines Bc10 and Zp4 in crosses with susceptible line Bc14. However, it was not confirmed in crosses with other susceptible inbreds (Bc2923, Bc252 and C123), which means that the dominant effect of alleles for resistance is dependent upon combination of crosses. In studyng resistance to stalk anthracnose as a quantitative trait, population of progenies from the same crosses were used as for leaf anthracnose.
In the total phenotypic variance, the variance of the environment accounts for the greatest part, therefore, heritability in broad seanse was in most crosses very small, and in some moderate. Heritability in the narrow sense except for being very small, in many cases of crossing it was negative. In one cross it was bigger than the heritability in the broad sense, which is a result of the negative parts of genotypic variances.
Doktor biotehničkih znanosti - agronomija
mentor: Zdravko Martinić-Jerčić; Komisija za ocjenu: Zdravko Martinić-Jerčić, Bogdan Cvjetković, Dragomir Parlov; Komisija za obranu: Bogdan Cvjetković, Zdravko Martinić-Jerčić, Dragomir Parlov; datum obrane 24.03.1995.; datum promocije 10.05.1996.
Sveučilište u Zagrebu, Agronomski fakultet, Zagreb, 1995
Bibliografija: str. 96-102
Summary
Keywords: Kukuruz -- Gljivične bolesti