Indirect Selection for Resistance to the Fusarium Wilt-Root-Knot Nematode Complex in Cotton1
- A. J. Kappelman and
- L. S. Bird2
The reaction to fusarium wilt [Fusarium oxysporum Schlect. f. vasinfectum (Atk.) Synd. & Hans.] and rootknotnematode (Meloidogyne spp.) of nine families and cultivars of cotton (Gossypium hirsutum L.) that were developed using the multi-adversity resistance (MAR) selection program, was compared with that of susceptible ‘Rowden’ and resistant ‘McNair 511.’ These materials were field tested at Tallassee, Ala., in 1974, 1975, and 1976 growing seasons. Use of the MAR technique increased the resistance of strain composites for four new families by recombination of strains within families. The mean wilt resistance over 3 years of all nine of the final strains or composites of strains representing families developed by this indirect MAR selection technique was greater than that in Rowden, while resistance in seven of these strains was equal to that of McNair 511. Two older MAR cultivars, ‘Tamcot SP 21’ and ‘Tamcot SP 37,’ developed during the early phases of the MAR program, were less susceptible than Rowden but only Tamcot SP 21 was as resistant as McNair 511. Three new MAR cultivars, ‘Tamcot SP 21S,’ ‘Tamcot SP 37H,’ and ’Tamcot CAMD-E; released from the composite cultivars tested during 1974, 1975, and 1976, and evaluated in 1978 had resistance equal to that of McNair 511 and were significantly less susceptible than Rowden. The high degree and rapid development of resistance in these composites achieved through indirect selection indicates that use of the MAR breeding technique can contribute significantly to the development of fusarium wilt resistance in cotton.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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