A study of supernodulation pea mutants

Sidorova, K.K., Vlasova, E.Yu., Mishchenko, T.I.,
Glianenko, M.N. and Shumny, V.K.

Institute of Cytology and Genetics
Siberian Branch, Russian Academy of Sciences
Novosibirsk, Russia

 Five supernodulated mutants have been induced from the cultivar Rondo following exposure of dry seeds to EMC. Mutants K 10a, K 11a and K 12a come from the same M2 family; mutants K 21a and K 22a from another. Under greenhouse growth conditions with and without nitrates, nodule number in the mutants varied between 845 and 1300 per plant, considerably higher than that in wild type Rondo. Except for K 10a, all the mutants are not as tall nor as productive as Rondo (Table 1).

 Table 1. Productivity of the supernodulated mutants and the original cultivar

--------------------------------Per plant--------------------------------

Mutant Line

Height (cm)

Number of pods

Number of seeds

Seed weight (g)

cv. Rondo

69.1 3.8

4.1 0.3

15.1 1.7

5.2 0.6

K 10a

56.8 3.3

5.3 0.5

17.6 1.9

6.0 0.7

K 11a

53.2 2.8

4.4 0.6

12.7 2.2

4.6 0.8

K 12a

54.8 1.2

4.0 0.6

10.2 1.2

3.4 0.4

K 21a

27.7 0.8

<3.1 0.2

6.5 0.6

<1.8 0.2

K 22a





 Genetic analysis suggests that all mutants are monogenic recessive mutations with pleiotropy. Apart from supernodulation, the plants have shortened stems and short lateral roots. Crosses between mutants established that K 10a, K 11a and K 12a are allelic to each other and to the mutant nod3, the seeds of which was a courtesy of Prof. N.F. Weeden. Mutants K 21a and K 22a are allelic to each other, but not to the other supernodulated mutants induced from Rondo or to nod3. Thus, K 21a and K 22a represent mutations at a new locus in pea.